CN102735349A - Apparatus for measuring multiple parameters of laser - Google Patents

Abstract

The invention relates to a laser parameter measuring device, which belongs to the technical field of laser measurement. The device is composed of a computer, a power supply module, a control signal receiving module, a front optical lens, a near-field optical lens, a scientific CCD, a near-field electric translation stage, a far-field electric translation stage, a photoelectric probe, an optical wedge group, a mirror group, A laser measuring device composed of an attenuation sheet and an energy meter. The device can realize the single pulse laser energy, energy stability, wavelength, spectral distribution, pulse width, pulse waveform, near-field spot, softening factor, near-field modulation degree, M2 factor, divergence angle, pointing The measurement and calculation of properties, output signal-to-noise ratio, polarization direction, polarization degree, beam waist position, image transmission surface position, and Rayleigh distance. The measuring device can effectively improve the measuring efficiency and calculate the relevant parameters of the measured light beam, and has good practical significance.

Description

A laser multi-parameter measuring device

technical field

The invention relates to a novel laser measuring device, in particular to a laser parameter measuring device which integrates multiple instruments, and belongs to the technical field of laser measuring.

Background technique

In order to meet different needs, the output beam of a laser source needs to be measured in many aspects, such as: spectral width, spot size, spot modulation, Rayleigh distance, beam waist position, divergence angle, directivity, beam quality factor, Single pulse energy, energy stability, average power, power stability, repetition frequency, pulse width, pulse stability, output signal-to-noise ratio, polarization direction, polarization degree, etc. However, the existing laser parameter testing instruments can only test a single or closely related laser parameters, and cannot measure multiple parameters simultaneously and comprehensively across multiple aspects such as time domain, frequency domain, and energy. This makes it necessary to measure the output beam characteristics of the laser light source one by one with many instruments, which is time-consuming and labor-intensive, and the working state of the laser cannot be well grasped. For example, when measuring a laser with a repetition rate as low as one pulse per tens of minutes, an energy meter is used to measure the parameters of the pulse energy, a photodiode is combined with an oscilloscope to measure the parameters of the laser output in the time domain, and a beam quality analyzer is used to measure the ^M2 factor of the laser. The multi-step test is not only time-consuming and laborious, but also the laser parameters measured before and after correspond to different time states, which also makes the measurement results unable to reflect the real-time characteristics of the laser well.

For example, the laser parameter measurement device with the application number 200610167350.2 uses a diffuse reflection imaging light target to reflect the measured laser source, and then displays it after being processed by an image acquisition card. This device is limited to relevant parameters such as pulse width, frequency, and image that can be obtained by the image acquisition card, and cannot fully reflect the various states of the measured laser beam.

Contents of the invention

The purpose of the present invention is to solve the problems in the above-mentioned prior art, and provide a device capable of simultaneously collecting the frequency domain, time domain, and light spot parameters of the laser beam to be measured, and calculating the required parameters. The device can measure the central wavelength, spectral width, and spectral distribution in the frequency domain; the repetition frequency, pulse width, and pulse stability in the time domain; the spot size, spot modulation, divergence angle, directivity, and beam quality factor in space. ; Single pulse energy, energy stability, average power, power stability, output signal-to-noise ratio on energy/power; polarization direction and degree of polarization on ^polarization state; Parameter real-time measurement device. The device can simultaneously measure the frequency domain, time domain, energy/power, polarization state, and the comprehensive parameters calculated instantaneously, so as to realize comprehensive, efficient, real-time measurement and monitoring of the output characteristics of the laser light source, and provide support for laser debugging and research. Provides faster and more convenient measurements.

The invention provides a laser parameter measurement system, which includes a sliding support rod 1, a front large reflector 2, a rear large reflector 3, a large lens 4, a folding reflector 5, a front fixed reflector 6, a rear fixed reflector 9, a front Wedge 10, rear wedge 11, small lens 13, far-field CCD14, far-field electric translation stage 15, near-field CCD16, near-field electric translation stage 17, interface circuit board 18, power module 19, box 20, as shown in the figure 1. It can also include an energy meter 7, a rotating electromagnet 8, a polarization test unit 12, a photoelectric probe 21, and a spectrometer collecting head 22;

In the described technical solution, the sliding strut 1 is used to fix the front large reflector 2 and the rear large reflector 3;

In the technical solution, the front large reflector 2 and the rear large reflector 3 can slide on the sliding rod 1, so as to realize the measurement of light beams at different heights;

In the described technical solution, the large lens 4 is used to converge the laser beam to be measured;

In the described technical solution, the folding mirror 5 is used to bend the light beam;

In the described technical solution, the front fixed reflector 6 and the rear fixed reflector 9 are used to bend light beams;

In the described technical solution, the described energy meter 7 is used to collect and calculate the energy value;

In the described technical solution, the rotating electromagnet 8 is used to control the entry and removal of the attenuation sheet, and to control the transmitted energy of the beam to be measured;

In the described technical solution, the front wedge 10 and the rear wedge 11 are used to split the laser beam to be measured and turn it into the CCD;

In described technical scheme, described polarization test unit 12 is used for measuring the polarization direction and the polarization degree of laser beam, is made of CCD, attenuation sheet, PBS crystal;

In the technical solution, the small lens 13 is used to form an image transfer structure with the large lens 4, and at the same time achieve beam reduction and measure the laser cross-sectional spot;

In the described technical solution, the far-field CCD14 is used to collect far-field converging spot conditions, and is used to calculate relevant laser parameters;

In the described technical solution, the far-field electric translation stage 15 is used to control and move the far-field CCD 14 to calculate relevant laser parameters;

In the described technical solution, the near-field CCD16 is used to collect near-field light spots and to calculate relevant laser parameters;

In the described technical solution, the near-field electric translation stage 17 is used to control and move the near-field CCD 16 to calculate relevant laser parameters;

In the described technical solution, the described interface circuit board 18 is used to convert and amplify the trigger signal, and manipulate the rotating electromagnet 8;

In the described technical solution, the described power supply module 19 is used to supply power to the interface circuit board 18;

In the above technical solution, the box 20 constitutes the casing of the laser multi-parameter measuring device, providing support and protection for each component;

In the described technical solution, the photoelectric probe 21 is fixed at an appropriate position on the bottom plate of the box body, and is used to collect the time waveform of the optical pulse;

In the technical solution, the spectrometer collecting head 22 is fixed at a proper position on the bottom plate of the box body, and is used to collect the frequency domain waveform of the optical pulse.

Compared with the prior art, the present invention has the following advantages:

1. The device of the present invention can simultaneously measure the frequency domain, time domain, space, energy/power, and polarization state for the laser light source. This comprehensive measuring instrument spanning multiple aspects is different from existing instruments for the frequency domain, time domain There are essential differences in the testing of several parameters in a certain aspect, such as space, etc., and the device of the present invention can realize comprehensive, efficient, real-time measurement and monitoring of the output characteristics of the laser light source.

2. The device of the present invention can calculate complex laser beam parameters such as M2 factor in real time after realizing the real-time measurement of multiple parameters output by the laser light source, and perform statistical processing to obtain the relationship between these complex parameters, or complex parameters and other arbitrary parameters. The relationship curve between them, so as to better detect the output characteristics of the laser light source, but the existing instruments and devices cannot realize such a function.

Description of drawings

Figure 1 is a diagram of the internal structure of the laser multi-parameter measurement device.

Fig. 2 is a schematic diagram of the interface connection between the laser multi-parameter measuring device and the computer.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Example 1

As shown in Figure 1, it is a structural schematic diagram of an embodiment of a laser multi-parameter real-time measurement system of the present invention, including a sliding support rod 1, a front large mirror 1, a rear large mirror 2, a large lens 3, a large lens 4, and a folding mirror 5. Front fixed mirror 6, energy meter 7, rotating electromagnet 8, rear fixed mirror 9, front wedge 10, rear wedge 11, polarization test unit 12, small lens 13, far-field CCD 14, far-field electric translation Platform 15, near-field CCD 16, near-field electric translation stage 17, interface circuit board 18, power module 19, box body 20, photoelectric probe 21 and spectrometer acquisition head 22. The internal structure of the system is shown in Figure 1.

When measuring, adjust the direction and angle of the incident beam of the instrument so that the laser beam to be measured is converged by the large lens 3 and then reflected by the folded reflector 5 and the front fixed reflector 6. The light reflected by the fixed mirror 9 and split by the front wedge 10 and the rear wedge 11 enters the far-field CCD14 and the near-field CCD16 respectively. Adjust the far-field electric translation stage 15 and the near-field electric translation stage 17 to find a clear image position, then collect the images of each CCD, and realize real-time calculation through software to obtain various required parameters. At the same time, the photoelectric probe and the spectrometer collecting head 22 collect measurement information in time domain and frequency domain.

The laser multi-parameter measurement device can realize the measurement of frequency-domain related parameters such as central wavelength, spectral width, spectral distribution, and spectral stability; and realize the measurement of time-domain related parameters such as repetition frequency, pulse width, pulse stability, and pulse waveform. ; Realize the measurement of space-related parameters such as spot size, spot modulation degree, divergence angle, and beam directivity; realize energy/power-related parameters such as single pulse energy, energy stability, average power, power stability, and output signal-to-noise ratio measurement; realize the measurement of relevant parameters such as polarization direction and degree of polarization; perform summary, calculation, and statistical processing of measurement results, which can be used to calculate relevant parameters such as beam waist position and M2 factor, and can be used to perform measurement results , Real-time drawing of the calculation result parameter correlation curve.

Example 2

The system includes a sliding strut 1, a front large reflector 1, a rear large reflector 2, a large lens 3, a large lens 4, a folding reflector 5, a front fixed reflector 6, a rear fixed reflector 9, a front wedge 10, a rear Wedge 11, small lens 13, far-field CCD14, far-field electric translation stage 15, near-field CCD16, near-field electric translation stage 17, interface circuit board 18, power supply module 19, box body 20.

When measuring, adjust the direction and angle of the incident beam of the instrument so that the laser beam to be measured is converged by the large lens 3 and reflected by the folding mirror 5 and the front fixed mirror 6, and most of it is reflected by the rear fixed mirror 9 and the front wedge 10. The rear wedge 11 splits the light and enters the far-field CCD14 and the near-field CCD16 respectively. Adjust the far-field electric translation stage 15 and the near-field electric translation stage 17 to find a clear image position, then collect the images of each CCD, and realize real-time calculation through software to obtain various required parameters.

The laser multi-parameter measurement device can realize the measurement of space-related parameters such as spot size, spot modulation degree, divergence angle, and beam directivity; relevant parameters such as beam waist position, M2 factor, etc. can be obtained by summarizing, calculating, and statistical processing, which can be used to carry out Real-time drawing of parameter correlation curves of measurement results and calculation results.

Claims (7)

1. A laser parameter measuring device, comprising a sliding strut, a front large reflector, a rear large reflector, a large lens, a folded reflector, a front fixed reflector, a rear fixed reflector, a front wedge, a rear wedge, a small Lens, far-field CCD, far-field electric translation stage, near-field CCD, near-field electric translation stage, interface circuit board, power module, cabinet. It can also include energy meters, rotating electromagnets, polarization test units, photoelectric probes, and spectrometer acquisition heads. 2. according to the described laser parameter measuring device of claim 1, it is characterized in that, described sliding strut is used for fixing front large reflector and rear large reflector; Described front large reflector and rear large reflector are in The sliding rod can slide to realize the measurement of beams at different heights; the large lens is used to converge the laser beam to be measured; the folding mirror is used to bend the beam; the front The fixed reflector and the rear fixed reflector are used to refract the beam; the energy meter is used to collect and calculate the energy value; the rotating electromagnet is used to control the entry and exit of the attenuation sheet, and to control the transmitted energy of the beam to be measured ; The front wedge and the rear wedge are used to split the laser beam to be measured and fold it into the CCD; the polarization test unit is used to measure the polarization direction and degree of polarization of the laser beam, which is composed of CCD, attenuation sheet , PBS crystal composition; the small lens is used to form an image transfer structure with the large lens, and at the same time realize beam shrinkage, and measure the laser cross-section spot; the far-field CCD is used to collect the far-field convergent spot situation, and use to calculate relevant laser parameters; the far-field electric translation stage is used to control and move the far-field CCD to calculate relevant laser parameters; the near-field CCD is used to collect near-field spot conditions and to calculate relevant laser parameters ; The near-field electric translation stage is used to control the movement of the near-field CCD, and calculates relevant laser parameters; the interface circuit board is used to convert and amplify the trigger signal, and manipulate the rotating electromagnet; the power module is used for to supply power to the interface circuit board; the box constitutes the shell of the laser multi-parameter measuring device to provide support and protection for each component; the photoelectric probe is fixed at an appropriate position on the bottom plate of the box to collect the time waveform of the optical pulse ; The spectrometer acquisition head is fixed at an appropriate position on the bottom plate of the box body, and is used to acquire the frequency domain waveform of the optical pulse. 3. according to the described laser parameter measuring device of claim 1, it is characterized in that, described polarization test unit is used for measuring the polarization direction and the degree of polarization of laser beam, is made of CCD, attenuation sheet, PBS crystal; The signal light of injection First, the PBS is divided into two beams of s light and p light, and then the two beams of light are converged to the target surface of the CCD through a mirror, and the energy or energy of the two beams of light is determined by measuring the ratio of the sum of the gray values of the two spot images. The power ratio is used to realize the measurement of the polarization state and polarization angle; the attenuator for beam reduction is inserted in the stronger way to reduce the ratio of the two beams of light intensity and improve the measurement accuracy. 4. according to the described laser parameter measuring device of claim 3, it is characterized in that, described CCD can be replaced by two-quadrant detector or four-quadrant detector, and the degree of polarization is determined by measuring energy or power ratio of two parts; Alternatively, two calibrated photodiodes are combined with a differential comparison circuit to determine the degree of polarization through the collected voltage ratio. 5. according to the described laser parameter measurement device of claim 1, it is characterized in that, described near-field CCD is used for collecting near-field spot situation, and is used for calculating relevant laser parameter; Described near-field electric translation stage is used for controlling Moving the near-field CCD to calculate relevant laser parameters. 6. The laser parameter measuring device according to claim 1, characterized in that, the large lens and the small lens constitute a laser beam diameter changing structure with an image transfer function, which can expand the diameter of the laser beam by 1 to 20 times. Or at the same time of zooming out, the light spot on the object plane at the front focus of the large lens is imaged onto the CCD detection surface, and the diffraction fringes are eliminated through the image transfer structure. 7. The laser parameter measurement device according to claim 1, characterized in that, the sliding strut, the front large reflector, and the rear large reflector can adjust the pitch and tilt angles by electric or manual adjustment to realize the adjustment of the incident beam. Adaptation of the light beam in the inclination range of ±5 degrees; the folding mirror, the front fixed mirror, the rear fixed mirror, the front wedge, and the rear wedge constitute a compact folding structure. On the basis of ensuring the image transfer structure, at the same time Beam delivery and multi-beam splitting are realized, providing 2 to 10 sub-beams for multi-parameter measurement systems.

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