CN114204412A - Laser generator and method for generating laser - Google Patents

Abstract

Embodiments of the present disclosure provide a laser generator and a method for generating laser light. The laser generator includes: a narrow pulse output module and a semiconductor laser module connected in sequence; wherein the narrow pulse output module is configured to When triggering a signal, the trigger signal is expanded into a first pulse signal and a second pulse signal; wherein, the first pulse signal and the second pulse signal have opposite phases; the narrow pulse output module is also configured as performing delay processing on the first pulse signal relative to the second pulse signal, and performing a logical operation on the second pulse signal and the delayed first pulse signal to obtain a target narrow pulse signal, and The target narrow pulse signal is output to the semiconductor laser module; the semiconductor laser module is configured to output a narrow pulse laser according to the received target narrow pulse signal.

Description

Laser generator and method for generating laser

technical field

The present disclosure relates to the technical field of lasers, and in particular, to a laser generator and a method for generating laser light.

Background technique

Narrow-pulse laser light sources with high repetition rates are necessary equipment for quantum communication. At present, there are various commercial laser products on the market. The operating frequency of these lasers is up to 100MHz, and the width at half maximum is less than 40ps; or the maximum operating frequency is 1.25GHz, and the width at half maximum is less than 50ps. However, with the continuous development and upgrading of quantum communication technology, higher requirements are put forward for the working frequency of lasers. The existing lasers are obviously inconvenient and defective in actual use, and it is necessary to improve them.

SUMMARY OF THE INVENTION

According to a first aspect of the embodiments of the present disclosure, a laser generator is provided, the laser generator comprising: a narrow pulse output module and a semiconductor laser module connected in sequence; wherein,

The narrow pulse output module is configured to expand the trigger signal into a first pulse signal and a second pulse signal when receiving a trigger signal; wherein the phase of the first pulse signal and the second pulse signal is on the contrary;

The narrow pulse output module is further configured to perform delay processing on the first pulse signal relative to the second pulse signal, and perform delay processing on the second pulse signal and the delayed first pulse signal performing a logical operation to obtain a target narrow pulse signal, and outputting the target narrow pulse signal to the semiconductor laser module;

The semiconductor laser module is configured to output narrow pulse laser light according to the received target narrow pulse signal.

In some embodiments, the narrow pulse output module includes: a first comparator, a delay component, a logic AND gate, a second comparator and an amplifying component connected in sequence, the first output end of the delay component and the first output terminal of the delay component The two output terminals are respectively connected with the two input terminals of the logic AND gate; wherein,

the first comparator, configured to filter the trigger signal and output it to the delay component after receiving the trigger signal;

The delay component is configured to expand the filtered trigger signal into the first pulse signal and the second pulse signal, and perform the delay processing on the first pulse signal;

The logical AND gate is configured to perform a logical operation on the second pulse signal and the delayed first pulse signal to obtain an initial narrow pulse signal, and output the initial narrow pulse signal to the first pulse signal. two comparators;

the second comparator, configured to filter the initial narrow pulse signal and output it to the amplifying component;

The amplifying component is configured to perform amplitude enhancement processing on the filtered initial narrow pulse signal to obtain a target narrow pulse signal, and output the target narrow pulse signal to the semiconductor laser module.

In some embodiments, the delay component includes:

a buffer including a first output port and a second output port, the first output port is configured to output the first pulse signal, the second output port is configured to output the second pulse signal;

a first signal line, electrically connecting the first output port and the first input port of the logic AND gate;

The second signal line is electrically connected to the second output port and the second input port of the logic AND gate; wherein the length of the first signal line is greater than the length of the second signal line.

In some embodiments, the amplifying assembly includes a first amplifier and a second amplifier electrically connected in sequence; wherein,

The first amplifier is configured to perform one-stage amplitude enhancement processing on the filtered initial narrow pulse signal to obtain an amplified narrow pulse signal;

The second amplifier is configured to perform a secondary amplitude enhancement process on the amplified narrow pulse signal to obtain a target narrow pulse signal, and output the target narrow pulse signal to the semiconductor laser module, wherein the first narrow pulse signal is The gain parameters of one amplifier and the second amplifier are different.

In some embodiments, the laser generator further includes:

a first capacitor, one end of the first capacitor is connected to the output end of the second radio frequency amplifier, and the other end of the first capacitor is connected to the input end of the semiconductor laser module; the first capacitor is configured In order to couple the target narrow pulse signal output by the narrow pulse output module to the semiconductor laser module.

In some embodiments, the signal parameters of the target narrow pulse signal include at least one of the following signal parameters: the operating frequency is 2GHz to 3GHz; the signal amplitude is greater than 3V; the pulse width is less than 200 picoseconds.

In some embodiments, the laser generator further includes: a control unit, a digital-to-analog converter, and a voltage follower connected in sequence, and the output end of the voltage follower is connected to the control end of the semiconductor laser module; wherein,

The control unit is configured to generate a digital control signal according to the received laser generating instruction and output it to the digital-to-analog converter;

The digital-to-analog converter is configured to receive a digital control signal output by the control unit, and convert the digital control signal into an analog control signal and output it to the voltage follower;

The voltage follower is configured to adjust the bias voltage of the semiconductor laser module according to the received analog control signal, so as to adjust the output laser parameter of the semiconductor laser module.

In some embodiments, the semiconductor laser module includes: a semiconductor cooling chip and a semiconductor laser; the semiconductor laser is disposed on the semiconductor cooling chip;

The laser generator also includes:

a temperature control module, one end of the temperature control module is electrically connected to the control unit, and the other end of the temperature control module is electrically connected to the semiconductor refrigeration chip,

The temperature control module is configured to output a current control signal to the semiconductor refrigeration chip according to the received temperature control signal output by the control unit;

The semiconductor cooling chip is configured to change the current according to the received current control signal, so as to change the temperature of the semiconductor cooling chip, so as to change the temperature of the semiconductor laser.

In some embodiments, the pulse repetition frequency of the narrow pulse laser is 2GHz to 3GHz;

and / or,

The width at half maximum of the narrow pulse laser is less than 50 picoseconds.

According to a second aspect of the embodiments of the present disclosure, there is provided a method for generating laser light, the method for generating laser light includes:

When a trigger signal is received, the trigger signal is expanded into a first pulse signal and a second pulse signal; wherein the first pulse signal and the second pulse signal have opposite phases;

performing delay processing on the first pulse signal relative to the second pulse signal, and performing a logical operation on the second pulse signal and the delayed first pulse signal to obtain a target narrow pulse signal;

The narrow pulse laser is output according to the target narrow pulse signal.

The laser generator provided by the embodiment of the present disclosure expands the trigger signal into two pulse signals with opposite phases through the narrow pulse output module, namely the first pulse signal and the second pulse signal. If delay processing is performed, a certain delay difference is generated between the first pulse signal and the second pulse signal, and a logic operation is performed on the second pulse signal and the delayed first pulse signal to form a pulse width with the delay difference as the pulse width. The target narrow pulse signal, the semiconductor laser module generates a narrow pulse laser with the same repetition frequency and pulse width as the target narrow pulse signal. Since the delay difference obtained by the delay processing is extremely short, the pulse width of the target narrow pulse signal is extremely narrow. When a trigger signal with a high frequency is used, a narrow pulse laser with a high pulse repetition frequency and a narrow pulse width can be output according to the target narrow pulse signal. Compared with the traditional method of using expensive and complex equipment to generate laser light, the method of generating the narrow pulse laser in the embodiment of the present disclosure is simpler, and in the delay processing, the delay time can also be adjusted by adjusting the delay time. The pulse width of the generated narrow pulse can flexibly generate the required narrow pulse laser.

Description of drawings

FIG. 1 is a schematic block diagram of a laser generator according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of a circuit structure of a narrow pulse output module of a laser generator according to an embodiment of the present disclosure;

3 is a schematic diagram of a delay processing waveform of a laser generator according to an embodiment of the present disclosure;

4 is a schematic diagram of a circuit structure of a laser generator provided by an embodiment of the present disclosure;

FIG. 5 is a schematic first flowchart of a method for generating laser light according to an embodiment of the present disclosure.

Description of reference numerals

100-narrow pulse output module; 200-semiconductor laser module; 300-control unit; 400-temperature control module; 101-first comparator; 102-delay component; 103-logic AND gate; 104-second comparator; 105-amplification component; B-buffer; L1-first signal line; L2-second signal line; A1-first amplifier; A2-second amplifier; C1-first capacitor; DAC-digital-to-analog converter; VF -Voltage follower; L1-first inductor; TEC-semiconductor refrigeration chip; LD-semiconductor laser.

Detailed ways

In order to make the technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the present disclosure will be further elaborated below with reference to the accompanying drawings and specific embodiments of the description.

The term "epitaxial" as used herein refers to the step of growing a semiconductor layer on a substrate.

In the embodiments of the present disclosure, the terms "first", "second", etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence.

In the embodiments of the present disclosure, unless otherwise expressly specified and limited, the "upper" or "lower" relationship between two layers in the semiconductor structure may be direct contact between the two layers, or indirect contact between the two layers through an intermediate layer .

In embodiments of the present disclosure, the term "layer" refers to a portion of a material that includes a region having a thickness. A layer may extend over the entirety of the underlying or overlying structure, or may have an extent that is less than the extent of the underlying or overlying structure. Furthermore, a layer may be a region of a homogeneous or heterogeneous continuous structure having a thickness less than the thickness of the continuous structure. For example, the layers may be located between the top and bottom surfaces of the continuous structure, or the layers may be between any horizontal faces at the top and bottom surfaces of the continuous structure. Layers may extend horizontally, vertically and/or along inclined surfaces. Also, a layer may include multiple sub-layers.

The laser generator of the present disclosure will be described in detail below with reference to the accompanying drawings.

An embodiment of the present disclosure provides a laser generator, and FIG. 1 is a schematic block diagram of a laser generator according to an embodiment of the present disclosure. As shown in FIG. 1 , the laser generator includes: a narrow pulse output module 100 and a semiconductor laser module 200 connected in sequence; wherein,

The narrow pulse output module 100 is configured to, when receiving the trigger signal, expand the trigger signal into a first pulse signal and a second pulse signal; wherein the first pulse signal and the second pulse signal have opposite phases;

The narrow pulse output module 100 is further configured to perform delay processing on the first pulse signal relative to the second pulse signal, and perform logical operations on the second pulse signal and the delayed first pulse signal to obtain a target narrow pulse signal , and output the target narrow pulse signal to the semiconductor laser module 200;

The semiconductor laser module 200 is configured to output narrow pulse laser light according to the received target narrow pulse signal.

The source of the trigger signal includes, but is not limited to, can be generated by a field programmable logic device FPGA. The trigger signal is input to the narrow pulse output module 100, and the repetition frequency of the trigger signal can be set by the host computer through the communication interface of the FPGA. In practical applications, the repetition frequency of the trigger signal can be set according to specific conditions.

In some embodiments, the narrow pulse output module 100 may include a delay component, and the delay component is configured to expand the trigger signal into a first pulse signal and a second pulse signal, and perform delay processing on the first pulse signal.

In practical applications, the second pulse signal without delay and the first pulse signal delayed by a preset time are output through the delay component. The preset delay time may include 50 to 500 picoseconds. Here, the preset time delay may include 200 picoseconds, so that the output delayed first pulse signal is delayed by 200 picoseconds relative to the second pulse signal.

In some embodiments, the narrow pulse output module 100 may include a logic block configured to perform a logical AND operation on the second pulse signal without delay and the first pulse signal after delay to obtain the target narrow pulse signal.

Here, the logic block can use a logic AND gate, and the AND operation of the input signal is performed through the logic AND gate to output the target narrow pulse signal. The preset time delay can include 200 picoseconds, then the target narrow pulse signal output by the delayed first pulse signal and the second pulse signal without delay through the logical AND gate is a narrow pulse signal with a width of 200 picoseconds .

In some embodiments, the semiconductor laser module 200 includes a semiconductor laser that can output narrow pulse laser light according to the received target narrow pulse signal.

In practical applications, the semiconductor laser is a laser diode, the target narrow pulse signal is coupled to the laser diode, and the laser diode generates a narrow pulse laser with the same repetition frequency and pulse width as the target narrow pulse signal.

In the embodiment of the present disclosure, the delay processing of the first pulse signal relative to the second pulse signal is performed, and a certain delay difference is generated between the first pulse signal and the second pulse signal, and the second pulse signal and the delayed first pulse signal have a certain delay difference. After the pulse signal is logically operated, the target narrow pulse signal with the delay difference as the pulse width is formed. Since the delay difference obtained by the delay processing is extremely short, the pulse width of the target narrow pulse signal is extremely narrow. , a narrow pulse laser with high pulse repetition frequency and narrow pulse width can be output according to the target narrow pulse signal. Compared with the traditional method of using expensive and complex equipment to generate laser light, the method of generating the narrow pulse laser in the embodiment of the present disclosure is simpler, and in the delay processing, the delay time can also be adjusted by adjusting the delay time. The pulse width of the generated narrow pulse can flexibly generate the required narrow pulse laser.

In some embodiments, referring to FIG. 2 , the narrow pulse output module 100 includes: a first comparator 101 , a delay component 102 , a logic AND gate 103 , a second comparator 104 , and an amplification component 105 connected in sequence, and the delay component 102 The first output end and the second output end of , are respectively connected with the two input ends of the logic AND gate 103; wherein,

The first comparator 101 is configured to, when receiving the trigger signal, filter the trigger signal and output it to the delay component 102;

The delay component 102 is configured to expand the filtered trigger signal into a first pulse signal and a second pulse signal, and perform delay processing on the first pulse signal;

The logical AND gate 103 is configured to perform a logical operation on the second pulse signal and the delayed first pulse signal to obtain an initial narrow pulse signal, and output the initial narrow pulse signal to the second comparator 104;

The second comparator 104 is configured to filter the initial narrow pulse signal and output it to the amplifying component 105;

The amplifying component 105 is configured to perform amplitude enhancement processing on the filtered initial narrow pulse signal to obtain the target narrow pulse signal, and output the target narrow pulse signal to the semiconductor laser module 200 .

In some embodiments, the trigger signal is generally a rising edge signal, and the pulse width is not limited. In this embodiment, the input trigger signal may be a clock signal with a repetition frequency of 2.5 GHz and an unlimited pulse width. The trigger signal may have some interference after a certain transmission distance. In order to improve the signal quality of the trigger signal, when receiving the trigger signal, the narrow pulse output module 100 filters the trigger signal through the first comparator 101 and outputs it to the delay component 102.

Here, the first comparator 101 may be a high-speed comparator. Through the transmission of the high-speed comparator, on the one hand, the signal pulse width of the trigger signal can be made narrower, and on the other hand, part of the noise in the trigger signal can be filtered out. Specifically, the model of the first comparator 101 can be ADCMP567, which can be set according to specific conditions in practical applications.

In some embodiments, the delay component 102 may include a buffer B configured to expand the filtered trigger signal into a first pulse signal and a second pulse signal of opposite phases, and a delay line.

Specifically, the buffers may include clock buffers. The filtered trigger signal is expanded into two pulse signals with the same signal amplitude through the clock buffer, and the phases of the two pulse signals are opposite.

Here, the delay line may include a first signal line L1 and a second signal line L2, wherein the length of the first signal line L1 is greater than the length of the second signal line L2. Delay processing is performed on the first pulse signal through the first signal line L1.

In practical applications, the delay preset time can be set by the host computer through the communication interface of the FPGA. The unit of delay preset time is generally based on the width at half width of the final output narrow pulse laser. For example, the width at half width of the output narrow pulse is required to be 50 picoseconds, then the preset delay time can be set to 50 picoseconds multiples, such as 50 ps, 100 ps, 150 ps, 200 ps, etc. Here, the preset time of the delay is set to 200 picoseconds, but the preset time of the delay is not limited to this, and can be set according to specific conditions in practical applications.

In some embodiments, the logical AND gate 103 performs an AND operation of the input signal on the second pulse signal and the delayed first pulse signal to obtain an initial narrow pulse signal with a pulse width of 200 picoseconds.

Here, the logical AND gate 103 can be a high-speed logical AND gate, which is implemented by a basic two-input high-speed logical AND gate.

In some embodiments, the edges of the signal may be degraded and distorted after the initial narrow pulse signal has traveled a certain distance. In order to ensure the steepness of the signal edge in the pulse signal, the second comparator 104 filters the initial narrow pulse signal which is processed by delay and output by the logical AND gate.

Here, the second comparator 104 can be a high-speed comparator, and the model of the second comparator 104 can be ADCMP567, which can be set according to specific conditions in practical applications. Through the second comparator 104, on the one hand, the signal pulse width of the initial narrow pulse signal can be made narrower, and on the other hand, interference pulses in the initial narrow pulse signal can be filtered out. The pulse width of the initial narrow pulse signal thus obtained by the second comparator 104 is about 120 picoseconds, and the amplitude is about 200 millivolts.

In some embodiments, since the pulse width of the filtered initial narrow pulse signal is narrow but the amplitude is low, in order to increase the signal amplitude of the filtered initial narrow pulse signal, the amplifying component 105 performs a Amplitude enhancement processing to obtain the target narrow pulse signal.

In practical applications, a target narrow pulse signal with a larger amplitude and a narrower pulse width is obtained through the amplifying component 105, and the target narrow pulse signal is a negative narrow pulse signal, wherein the negative narrow pulse signal is a jump from a high level to a narrow pulse signal. Low level, and then a narrow pulse signal that jumps from low level to high level. That is to say, the waveform change of the negative narrow pulse signal is a falling edge first, then a low level for a period of time, and then a rising edge.

In the embodiment of the present disclosure, the amplification component 105 performs amplitude enhancement processing on the signal to obtain a signal with a relatively large amplitude and a relatively narrow pulse width, which further improves the quality of the pulse signal and enables the signal parameters of the target narrow pulse signal to meet the requirements for outputting the narrow pulse laser. Finally, the narrow pulse laser with high pulse repetition frequency and narrow pulse width can be output according to the target narrow pulse signal.

In the embodiment of the present disclosure, a narrow pulse signal with the delay difference as the pulse width is formed after delay processing and logical operation, but in order to further improve the signal quality of the narrow pulse signal, the first comparator 101 and the second comparison The device 104 performs signal filtering processing to make the signal pulse width of the signal narrower, filters out part of the noise in the signal, and performs amplitude enhancement processing on the signal through the amplifying component 105 to obtain a signal with a larger amplitude and a narrower pulse width. The narrow pulse laser with high pulse repetition frequency and narrow pulse width can be output according to the target narrow pulse signal, so as to meet the requirements of the narrow pulse laser light source.

In some embodiments, with continued reference to FIG. 2 , the delay component 102 includes:

the buffer B, including a first output port and a second output port, the first output port is configured to output the first pulse signal, and the second output port is configured to output the second pulse signal;

The first signal line L1 is electrically connected to the first output port and the first input port of the logical AND gate 103;

The second signal line L2 is electrically connected to the second output port and the second input port of the logical AND gate 103; wherein the length of the first signal line L1 is greater than the length of the second signal line L2.

Referring to FIG. 3 , the filtered trigger signal is expanded into a first pulse signal and a second pulse signal with opposite phases through the buffer B. For these two pulse signals, where the length of the first signal line L1 is greater than the length of the second signal line L2, the line of the first pulse signal of the same phase is longer than the line of the second pulse signal of the opposite phase. The first pulse signal resulting in the same phase of the path arrives at the logical AND gate 103 later.

Here, the preset delay time can be calculated according to the formula ΔT=ΔL/V, where ΔT is the preset delay time, and ΔL is the difference between the trace lengths of the first signal line L1 and the second signal line L2 value, V is the transmission speed of the signal in the board. After delay processing, the two pulse signals are ANDed in the logic AND gate 103 to generate a narrow pulse signal with a pulse width of about 200 picoseconds. This process is shown in FIG. 3 .

In the embodiment of the present disclosure, the method of obtaining the narrow pulse signal through delay processing is more convenient, and when the delay processing is performed, the delay time length can be adjusted to further adjust the pulse width of the generated narrow pulse, so as to flexibly generate the required narrow pulse laser.

In some embodiments, with continued reference to FIG. 2 , the amplifying assembly 105 includes a first amplifier A1 and a second amplifier A2 that are electrically connected in sequence; wherein,

The first amplifier A1 is configured to perform a first-stage amplitude enhancement process on the filtered initial narrow pulse signal to obtain an amplified narrow pulse signal;

The second amplifier A2 is configured to perform two-stage amplitude enhancement processing on the amplified narrow pulse signal to obtain the target narrow pulse signal, and output the target narrow pulse signal to the semiconductor laser module 200, wherein the first amplifier A1 and the second amplifier A2 The gain parameters are different.

Here, the first amplifier A1 and the second amplifier A2 may be radio frequency amplifiers, and the gains of the first amplifier A1 and the second amplifier A2 can be adjusted. The gain parameters of the first amplifier A1 and the second amplifier A2 are different. The maximum gain of one RF amplifier is about 20dB, and the maximum gain of the other RF amplifier is about 16dB. By adjusting the gain of the first amplifier A1 and the second amplifier A2, a target narrow pulse signal with an amplitude greater than 3V is finally obtained.

In practical applications, the gain of a single-stage amplifier is higher than when a single-stage amplifier is used to achieve signal amplification. When the gain of the single-stage amplifier is comparable to that of the multi-stage amplifier, the stability of the single-stage amplifier is poor. In this embodiment, the first amplifier A1 and the second amplifier A2 can be used to achieve two-stage amplification, and other multi-stage amplification can also be used, which can be set according to specific conditions in practical applications.

Specifically, the first stage of amplification of the first amplifier A1 may be voltage amplification, which may remove the interference signal in the filtered initial narrow pulse signal, and perform amplitude amplification on the remaining signal after removing the interference signal. The second stage of amplification of the second amplifier A2 may be power amplification.

In some embodiments, referring to FIG. 4 , the laser generator further includes:

The first capacitor C1, one end of the first capacitor C1 is connected to the output end of the second radio frequency amplifier, and the other end of the first capacitor C1 is connected to the input end of the semiconductor laser module 200; the first capacitor C1 is configured to output narrow pulses The target narrow pulse signal output by the module 100 is coupled to the semiconductor laser module 200 .

In some embodiments, the semiconductor laser LD is a laser diode, and the first capacitor C1 can be coupled to the cathode of the laser diode in series.

The signal parameters of the target narrow pulse signal may include at least one of the following signal parameters: the operating frequency is 2GHz to 3GHz; the signal amplitude is greater than 3V; the pulse width is less than 200 picoseconds.

Here, the trigger signal can be a clock signal with a repetition frequency of 2.5GHz and an unlimited pulse width, and the signal parameters of the output target narrow pulse signal can include an operating frequency of 2.5GHz, a signal amplitude greater than 3V and a pulse width of less than 200 picoseconds. The signal parameters of the target narrow pulse signal are not limited to this, and can be adjusted according to the needs of outputting narrow pulse lasers in practical applications.

In practical applications, the first capacitor C1 couples the target narrow pulse signal output by the narrow pulse output module 100 to a laser diode, and the laser diode generates a narrow pulse laser with a repetition frequency of 2.5 GHz and a full width at half maximum of less than 200 picoseconds.

In the embodiment of the present disclosure, the output target narrow pulse signal can be coupled to the laser diode through the first inductor C1, and finally narrow pulse laser with high pulse repetition frequency and narrow pulse width can be output according to the target narrow pulse signal.

In some embodiments, continuing to refer to FIG. 4 , the laser generator further includes: a control unit 300 , a digital-to-analog converter DAC and a voltage follower VF connected in sequence, the output end of the voltage follower VF and the control end of the semiconductor laser module 200 connection; where,

The control unit 300 is configured to generate a digital control signal according to the received laser generating instruction and output it to the digital-to-analog converter DAC;

a digital-to-analog converter DAC, configured to receive the digital control signal output by the control unit 300, and convert the digital control signal into an analog control signal and output it to the voltage follower VF;

The voltage follower VF is configured to adjust the bias voltage of the semiconductor laser module 200 according to the received analog control signal, so as to adjust the output laser parameters of the semiconductor laser module 200 .

In some embodiments, the control unit 300 may be a field programmable logic device FPGA, and the control unit 300 performs control according to the laser generating instruction. The laser generating instruction can be input by the host computer through the communication interface of the FPGA, or the laser generating instruction can be programmed and stored in the FPGA in advance, and can be set according to specific conditions in practical applications.

In practical applications, the repetition frequency of the narrow-pulse laser generated by the laser diode is 2.5 GHz, and the full width at half maximum is less than 200 picoseconds.

In order to realize that the repetition frequency of the output narrow pulse laser is 2.5GHz and the pulse width is less than 50 picoseconds, it is necessary to set the bias voltage (Vbias) circuit of the laser diode. The bias voltage circuit can be composed of a digital-to-analog converter DAC and a voltage follower VF. The FPGA controls the magnitude of the bias voltage Vbias by controlling the output of the digital-to-analog converter DAC, thereby controlling the output laser parameters of the laser diode.

It should be noted that the laser generator further includes: a first inductor L1, one end of the first inductor L1 is connected to the output end of the voltage follower VF, and the other end of the first inductor L1 is connected to the input end of the semiconductor laser module 200; An inductor L1 is configured to couple the bias voltage output by the voltage follower VF to the semiconductor laser module 200 . The first inductor L1 is coupled in series to the cathode of the laser diode.

In some embodiments, a digital control signal is generated in the FPGA according to the received laser generating instruction, and is connected to the digital-to-analog converter DAC through the SPI serial bus. The digital-to-analog converter DAC converts the digital control signal output by the FPGA into an analog control signal, where the analog control signal is an analog voltage signal, that is, a bias voltage Vbias. The voltage follower VF does not change the bias voltage Vbias output by the digital-to-analog converter DAC, but transforms the output impedance of the digital-to-analog converter DAC to improve the carrying capacity.

Here, the first inductor L1 linearly converts the analog voltage signal output by the voltage follower VF into a current signal, which is output to the laser diode, and the current signal is used as the control current of the laser diode. The repetition frequency of the narrow pulse laser emitted by the laser diode according to the target narrow pulse signal is 2.5GHz, and the pulse width is less than 200 picoseconds. Observe the pulse width of the output narrow pulse laser through the change of the current signal. When the value of the bias voltage Vbias is adjusted to a certain value (the specific value is related to the waveform of the target narrow pulse signal and needs to be adjusted according to the specific situation), repeated A narrow pulse laser with a frequency of 2.5GHz and a full width at half maximum of less than 50 picoseconds.

In practical applications, the bias voltage Vbias output by the digital-to-analog converter DAC can be adjusted between 0 and -1.5V, and the control current output by the voltage follower VF for driving the laser diode needs to be greater than 50 mA to meet the requirements of the laser diode. drive requirements.

In the embodiment of the present disclosure, by setting the bias voltage (Vbias) circuit of the laser diode, the bias voltage circuit may be composed of a digital-to-analog converter DAC and a voltage follower VF, and the FPGA controls the bias voltage by controlling the output of the digital-to-analog converter DAC. Set the size of the voltage Vbias, so as to control the output laser parameters of the laser diode. The narrow pulse laser with a repetition frequency of 2.5GHz and a pulse width of less than 200 picoseconds is adjusted to a narrow pulse laser with a repetition frequency of 2.5GHz and a pulse width of less than 50 picoseconds, and finally a narrow pulse with a high pulse repetition frequency and a narrow pulse width can be output. laser.

In some embodiments, continuing to refer to FIG. 4 , the semiconductor laser module 200 includes: a semiconductor cooling sheet TEC and a semiconductor laser LD; the semiconductor laser LD is disposed on the semiconductor cooling sheet TEC;

The laser generator also includes:

The temperature control module 400, one end of the temperature control module 400 is electrically connected to the control unit 300, and the other end of the temperature control module 400 is electrically connected to the semiconductor refrigeration chip TEC,

The temperature control module 400 is configured to output a current control signal to the semiconductor refrigeration chip TEC according to the received temperature control signal output by the control unit 300;

The semiconductor cooling chip TEC is configured to change the current according to the received current control signal, so as to change the temperature of the semiconductor cooling chip TEC, so as to change the temperature of the semiconductor laser LD.

In some embodiments, the semiconductor cooling chip TEC can control the laser frequency output by the semiconductor laser LD. By controlling the temperature of the semiconductor laser LD, the frequency of the laser light generated by the semiconductor laser LD is controlled to be near the repetition frequency of 2.5 GHz.

Here, the control unit 300 may be a field programmable logic device FPGA. The FPGA sets the operating temperature of the semiconductor laser LD, and the FPGA writes the temperature setting value to the temperature control module 400, and outputs the temperature setting value to the temperature control signal through the temperature control signal. Temperature control module 400 .

The temperature control module 400 converts the temperature control signal into a current control signal, and outputs the current control signal to the semiconductor refrigeration sheet TEC to change the current of the semiconductor refrigeration sheet TEC. When the temperature of the TEC reaches the temperature setting value, the semiconductor laser LD works at the temperature setting value, so as to avoid the influence of too high or too low temperature on the semiconductor laser LD, and the semiconductor laser LD can achieve stable laser output.

In practical applications, the temperature setting value may be a specific temperature value between 30°C and 60°C for the operating temperature of the semiconductor laser LD according to design requirements. Here, the temperature setting value of the semiconductor laser LD may be 35°C.

In the embodiment of the present disclosure, for every 1°C increase in temperature, the luminous intensity of the semiconductor laser LD may correspondingly decrease by about 1%, and the temperature change may also cause the wavelength of the output laser to change. Therefore, in order to enable the semiconductor laser LD to achieve stable laser output, the temperature of the semiconductor refrigeration sheet TEC can be adjusted to reach the temperature setting value, so that the semiconductor laser LD works at the temperature setting value, so as to avoid excessive or low temperature to the semiconductor laser LD. Impact.

Further, the pulse repetition frequency of the narrow pulse laser is 2GHz to 3GHz;

and / or,

The width at half maximum of the narrow pulse laser is less than 50 picoseconds.

In some embodiments, the signal parameters of the target narrow pulse signal include an operating frequency of 2.5GHz, a signal amplitude greater than 3V and a pulse width of less than 200 picoseconds, and the laser diode generates a narrow pulse with the same repetition frequency and pulse width as the target narrow pulse signal laser, the repetition frequency of the narrow pulse laser is 2.5GHz, and the pulse width is less than 200 picoseconds.

In practical applications, the FPGA controls the bias voltage Vbias of the laser diode by controlling the output of the digital-to-analog converter DAC, so as to control the output of the laser diode, and realize that the repetition frequency of the output narrow pulse laser is 2.5GHz, and the full width at half maximum is less than 50 picoseconds. The present disclosure realizes a narrow-pulse laser with a repetition frequency of 2.5 GHz and a full width at half maximum of less than 50 picoseconds, which can be used in fields such as quantum communication that require a narrow-pulse laser light source with a high repetition frequency.

According to a second aspect of the embodiments of the present disclosure, a method for generating laser light is provided. Referring to FIG. 5 , the method for generating laser light includes:

S10, when a trigger signal is received, expand the trigger signal into a first pulse signal and a second pulse signal; wherein the first pulse signal and the second pulse signal have opposite phases;

S20: Perform delay processing on the first pulse signal relative to the second pulse signal, and perform logical operations on the second pulse signal and the delayed first pulse signal to obtain a target narrow pulse signal ;

S30, output a narrow pulse laser according to the target narrow pulse signal.

In some embodiments, when the trigger signal is received, the trigger signal may be extended into a first pulse signal and a second pulse signal with opposite phases through a delay component, and the first pulse signal is processed relative to the second pulse signal. Delay processing.

In practical application, the phase of the first pulse signal and the second pulse signal are opposite, and the second pulse signal without delay and the first pulse signal delayed by a preset time are output through the delay component. The preset delay time may include 50 to 500 picoseconds. Here, the preset time delay may include 200 picoseconds, so that the output delayed first pulse signal is delayed by 200 picoseconds relative to the second pulse signal.

In some embodiments, the logic block may perform a logic operation on the second pulse signal without delay and the first pulse signal after delay to obtain the target narrow pulse signal.

Here, the logic block can use a logic AND gate, and the AND operation of the input signal is performed through the logic AND gate to output the target narrow pulse signal. The preset time delay can include 200 picoseconds, then the target narrow pulse signal output by the delayed first pulse signal and the second pulse signal without delay through the logical AND gate is a narrow pulse signal with a width of 200 picoseconds .

In some embodiments, the target narrow pulse signal is output to the semiconductor laser, and the semiconductor laser can output narrow pulse laser light according to the received target narrow pulse signal.

In practical applications, the semiconductor laser is a laser diode, the target narrow pulse signal is coupled to the laser diode, and the laser diode generates a narrow pulse laser with the same repetition frequency and pulse width as the target narrow pulse signal.

In some embodiments, the trigger signal is generally a rising edge signal, and the pulse width is not limited. In this embodiment, the input trigger signal may be a clock signal with a repetition frequency of 2.5 GHz and an unlimited pulse width. The trigger signal may have some interference after a certain transmission distance. In order to improve the signal quality of the trigger signal, when the trigger signal is received, the trigger signal is filtered and then expanded into a first pulse signal and a second pulse signal. Signal steps.

Here, by filtering the trigger signal, on the one hand, the signal pulse width of the trigger signal can be made narrower, and on the other hand, part of the noise in the trigger signal can be filtered out.

In step S30, the signal parameters of the target narrow pulse signal may include an operating frequency of 2.5 GHz, a signal amplitude greater than 3V and a pulse width of less than 200 picoseconds, and the laser diode that receives the target narrow pulse signal generates the same repetition as the target narrow pulse signal. Narrow pulse laser with frequency and pulse width, the repetition frequency of the narrow pulse laser is 2.5GHz, and the pulse width is less than 200 picoseconds.

Here, the magnitude of the bias voltage Vbias of the laser diode is controlled, thereby controlling the output of the laser diode, so that the repetition frequency of the output narrow pulse laser is 2.5 GHz, and the pulse width is less than 50 picoseconds. The present disclosure realizes a narrow-pulse laser with a repetition frequency of 2.5 GHz and a full width at half maximum of less than 50 picoseconds, which can be used in fields such as quantum communication that require a narrow-pulse laser light source with a high repetition frequency.

In the embodiment of the present disclosure, when a trigger signal is received, the trigger signal is expanded into a first pulse signal and a second pulse signal; wherein, the first pulse signal and the second pulse signal have opposite phases; Delay processing is performed on the pulse signal, and a logical operation is performed on the second pulse signal and the delayed first pulse signal to obtain a target narrow pulse signal; and a narrow pulse laser is output according to the target narrow pulse signal. Because the delay difference obtained by the delay processing is extremely short, the pulse width of the target narrow pulse signal is extremely narrow. When a trigger signal with a high frequency is input, a narrow pulse with a high pulse repetition frequency and a narrow pulse width can be output according to the target narrow pulse signal. laser. Compared with the traditional method of using expensive and complex equipment to generate laser light, the method of generating the narrow pulse laser in the embodiment of the present disclosure is simpler, and in the delay processing, the delay time can also be adjusted by adjusting the delay time. The pulse width of the generated narrow pulse can flexibly generate the required narrow pulse laser.

In some embodiments, step S20 includes:

The first pulse signal is transmitted through a first signal line, and the second pulse signal is transmitted through a second signal line; wherein the length of the first signal line is greater than the length of the second signal line;

performing a logical operation on the second pulse signal and the delayed first pulse signal to obtain an initial narrow pulse signal;

filtering the initial narrow pulse signal;

An amplitude enhancement process is performed on the filtered initial narrow pulse signal to obtain a target narrow pulse signal.

In practical application, the second pulse signal without delay is output through the second signal line, and the first pulse signal delayed by a preset time is output through the first signal line.

The unit of delay preset time is generally based on the width of half width of the final output narrow pulse laser. For example, the width at half maximum width of the output narrow pulse is 50 picoseconds, then the preset delay time can be set to a multiple of 50 picoseconds, such as 50 picoseconds, 100 picoseconds, 150 picoseconds, 200 picoseconds, etc. Here, the preset time of the delay is set to 200 picoseconds, but the preset time of the delay is not limited to this, and can be set according to specific conditions in practical applications.

In some embodiments, the AND operation of the input signal is performed on the second pulse signal and the delayed first pulse signal to obtain an initial narrow pulse signal with a pulse width of 200 picoseconds.

In some embodiments, the edges of the signal may be degraded and distorted after the initial narrow pulse signal has traveled a certain distance. In order to ensure the steepness of the signal edge in the pulse signal, the initial narrow pulse signal output by delay processing and logical AND operation is filtered.

Here, the initial narrow pulse signal can pass through a high-speed comparator, and the model of the high-speed comparator can be ADCMP567, which can be set according to specific conditions in practical applications. On the one hand, the high-speed comparator can make the signal pulse width of the initial narrow pulse signal narrower, and on the other hand, it can filter out the interference pulses in the initial narrow pulse signal. The resulting initial narrow pulse signal had a pulse width of about 120 picoseconds and an amplitude of about 200 millivolts.

In some embodiments, since the pulse width of the filtered initial narrow pulse signal is narrow but the amplitude is low, in order to increase the signal amplitude of the filtered initial narrow pulse signal, amplitude enhancement processing is performed on the filtered initial narrow pulse signal to Obtain the target narrow pulse signal.

In practical applications, a target narrow pulse signal with a large amplitude and a narrow pulse width is obtained through amplitude enhancement processing, and the target narrow pulse signal is a negative narrow pulse signal. Among them, the negative narrow pulse signal is a narrow pulse signal that jumps from a high level to a low level, and then jumps from a low level to a high level. That is to say, the waveform change of the negative narrow pulse signal is a falling edge first, then a low level for a period of time, and then a rising edge.

Here, two-stage amplitude enhancement processing may be performed on the filtered initial narrow pulse signal to obtain the target narrow pulse signal. Wherein, two-stage amplitude enhancement processing can be implemented by the first amplifier and the second amplifier with different gain parameters.

In practical applications, the gain of a single-stage amplifier is higher than when a single-stage amplifier is used to achieve signal amplification. When the gain of the single-stage amplifier is comparable to that of the multi-stage amplifier, the stability of the single-stage amplifier is poor. In this embodiment, the first amplifier and the second amplifier may be used to achieve two-stage amplification, and other multi-stage amplification may also be used, which may be set according to specific conditions in practical applications. Here, the first amplifier and the second amplifier may be radio frequency amplifiers, and the gains of both the first amplifier and the second amplifier may be adjusted. Among them, the maximum gain of one RF amplifier is about 20dB, and the maximum gain of the other RF amplifier is about 16dB. By adjusting the gain of the first amplifier and the second amplifier, a target narrow pulse signal with an amplitude greater than 3V is finally obtained.

In some embodiments, after the trigger signal is input, the target narrow pulse signal is output through filtering processing, delay processing, logical AND operation, filtering again, and amplitude enhancement processing. The signal parameters of the target narrow pulse signal may include at least one of the following signal parameters: the operating frequency is 2GHz to 3GHz; the signal amplitude is greater than 3V; the pulse width is less than 200 picoseconds.

Here, the trigger signal can be a clock signal with a repetition frequency of 2.5GHz and an unlimited pulse width, and the signal parameters of the output target narrow pulse signal can include an operating frequency of 2.5GHz, a signal amplitude greater than 3V and a pulse width of less than 200 picoseconds. The signal parameters of the target narrow pulse signal are not limited to this, and can be adjusted according to the needs of outputting narrow pulse lasers in practical applications.

In some embodiments, a narrow pulse laser with the same repetition frequency and pulse width as the target narrow pulse signal is generated by a laser diode, the repetition frequency of the narrow pulse laser may be 2.5 GHz, and the pulse width is less than 200 picoseconds.

In practical applications, FPGA can be used to control the bias voltage Vbias of the laser diode by controlling the output of the digital-to-analog converter, so as to control the output of the laser diode, and realize that the repetition frequency of the output narrow pulse laser is 2.5GHz, and the full width at half maximum is less than 50 picoseconds, the present disclosure realizes a narrow pulse laser with a repetition frequency of 2.5 GHz and a full width at half maximum of less than 50 picoseconds, which can be used in fields such as quantum communication that require a narrow pulse laser light source with a high repetition frequency. In the embodiment of the present disclosure, a narrow pulse signal with the delay difference as the pulse width is formed through delay processing and logical operation. However, in order to further improve the signal quality of the narrow pulse signal, signal filtering processing is also performed through a high-speed comparator, so that the The signal pulse width of the signal becomes narrower, part of the noise in the signal is filtered out, and the amplitude enhancement process is performed on the signal to obtain a signal with a larger amplitude and a narrower pulse width, which can finally output a high pulse repetition frequency and a high pulse repetition frequency according to the target narrow pulse signal. Narrow pulse laser with narrow pulse width to meet the needs of narrow pulse laser light source.

In the several embodiments provided in the present disclosure, it should be understood that the disclosed apparatus and method may be implemented in other manners. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined, or Can be integrated into another system, or some features can be ignored, or not implemented. In addition, the coupling, or direct coupling, or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical or other forms. of.

The unit described above as a separate component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units; Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present disclosure may be all integrated into one processing module, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above integration The unit can be implemented either in the form of hardware or in the form of hardware plus software functional units. Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by program instructions related to hardware, the aforementioned program may be stored in a computer-readable storage medium, and when the program is executed, execute Including the steps of the above method embodiment; and the aforementioned storage medium includes: a mobile storage device, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk and other various A medium on which program code can be stored.

The methods disclosed in the several method embodiments provided in the present disclosure can be combined arbitrarily without conflict to obtain new method embodiments.

The features disclosed in the several product embodiments provided in the present disclosure can be combined arbitrarily without conflict to obtain a new product embodiment.

The features disclosed in several method or device embodiments provided in the present disclosure can be combined arbitrarily without conflict to obtain new method embodiments or device embodiments.

The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited to this. should be included within the scope of protection of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims (10)

1. A laser generator, comprising: the narrow pulse output module and the semiconductor laser module are connected in sequence; wherein,

the narrow pulse output module is configured to expand a trigger signal into a first pulse signal and a second pulse signal when the trigger signal is received; wherein the first pulse signal and the second pulse signal are opposite in phase;

the narrow pulse output module is further configured to perform time delay processing on the first pulse signal relative to the second pulse signal, perform logical operation on the second pulse signal and the time-delayed first pulse signal to obtain a target narrow pulse signal, and output the target narrow pulse signal to the semiconductor laser module;

the semiconductor laser module is configured to output narrow-pulse laser light according to the received target narrow-pulse signal.

2. The laser generator of claim 1, wherein the narrow pulse output module comprises: the delay circuit comprises a first comparator, a delay component, a logic AND gate, a second comparator and an amplification component which are connected in sequence, wherein a first output end and a second output end of the delay component are respectively connected with two input ends of the logic AND gate; wherein,

the first comparator is configured to filter the trigger signal and output the filtered trigger signal to the delay component when the trigger signal is received;

the delay component is configured to expand the filtered trigger signal into the first pulse signal and the second pulse signal, and perform the delay processing on the first pulse signal;

the logic AND gate is configured to perform a logic operation on the second pulse signal and the delayed first pulse signal to obtain an initial narrow pulse signal, and output the initial narrow pulse signal to the second comparator;

the second comparator is configured to filter the initial narrow pulse signal and output the filtered initial narrow pulse signal to the amplifying component;

the amplifying component is configured to perform amplitude enhancement processing on the filtered initial narrow pulse signal to obtain a target narrow pulse signal, and output the target narrow pulse signal to the semiconductor laser module.

3. The laser generator of claim 2, wherein the delay assembly comprises:

a buffer including a first output port configured to output the first pulse signal and a second output port configured to output the second pulse signal;

the first signal wire is electrically connected with the first output port and the first input port of the logic AND gate;

the second signal wire is electrically connected with the second output port and a second input port of the logic AND gate; wherein the length of the first signal line is greater than the length of the second signal line.

4. The laser generator of claim 2, wherein the amplification assembly comprises a first amplifier and a second amplifier electrically connected in series; wherein,

the first amplifier is configured to perform one-stage amplitude enhancement processing on the filtered initial narrow pulse signal to obtain an amplified narrow pulse signal;

the second amplifier is configured to perform two-stage amplitude enhancement processing on the amplified narrow pulse signal to obtain a target narrow pulse signal, and output the target narrow pulse signal to the semiconductor laser module, wherein gain parameters of the first amplifier and the second amplifier are different.

5. The laser generator of claim 2, further comprising:

one end of the first capacitor is connected with the output end of the second radio frequency amplifier, and the other end of the first capacitor is connected with the input end of the semiconductor laser module; the first capacitor is configured to couple the target narrow pulse signal output by the narrow pulse output module to the semiconductor laser module.

6. The laser generator of claim 1, wherein the signal parameters of the target narrow pulse signal comprise at least one of: the working frequency is 2GHz to 3 GHz; the signal amplitude is greater than 3V; the pulse width is less than 200 picoseconds.

7. The laser generator of claim 1, further comprising: the output end of the voltage follower is connected with the control end of the semiconductor laser module; wherein,

the control unit is configured to generate a digital control signal according to the received laser generation instruction and output the digital control signal to the digital-to-analog converter;

the digital-to-analog converter is configured to receive the digital control signal output by the control unit and convert the digital control signal into an analog control signal to be output to the voltage follower;

the voltage follower is configured to adjust a bias voltage of the semiconductor laser module according to the received analog control signal to adjust an output laser parameter of the semiconductor laser module.

8. The laser generator of claim 7,

the semiconductor laser module includes: the semiconductor refrigeration chip and the semiconductor laser; the semiconductor laser is arranged on the semiconductor refrigerating sheet;

the laser generator further includes:

one end of the temperature control module is electrically connected with the control unit, the other end of the temperature control module is electrically connected with the semiconductor refrigeration sheet,

the temperature control module is configured to output a current control signal to the semiconductor chilling plate according to the received temperature control signal output by the control unit;

the semiconductor chilling plate is configured to change current according to the received current control signal so as to change the temperature of the semiconductor chilling plate and change the temperature of the semiconductor laser.

9. The laser generator according to any of claims 1 to 8,

the pulse repetition frequency of the narrow pulse laser is 2GHz to 3 GHz;

and/or the presence of a gas in the gas,

the full width at half maximum of the narrow pulse laser is less than 50 picoseconds.

10. A method of lasing, the method comprising:

expanding a trigger signal into a first pulse signal and a second pulse signal upon receiving the trigger signal; wherein the first pulse signal and the second pulse signal are opposite in phase;

delaying the first pulse signal relative to the second pulse signal, and performing logic operation on the second pulse signal and the delayed first pulse signal to obtain a target narrow pulse signal;

and outputting narrow pulse laser according to the target narrow pulse signal.

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