CN113534359A

CN113534359A - Optical module

Info

Publication number: CN113534359A
Application number: CN202010317416.1A
Authority: CN
Inventors: 邵乾; 刘维伟; 张占鹏; 任乐燕
Original assignee: Hisense Broadband Multimedia Technology Co Ltd
Current assignee: Hisense Broadband Multimedia Technology Co Ltd
Priority date: 2020-04-21
Filing date: 2020-04-21
Publication date: 2021-10-22

Abstract

The application discloses optical module includes: circuit board and light emitting device, the light emitting device includes: a TO tube seat; the TO tube cap is covered on the TO tube seat; the laser is arranged on the surface of the TO tube seat and used for emitting signal beams, and the light emitting direction of the laser is not consistent with the light transmitting direction of the TO tube cap; the reflecting mirror is provided with a bottom platform, a top platform and an inclined plane, the bottom platform is fixed on the TO tube seat, and the inclined plane is used for reflecting the signal light beam from the laser so that the light emitting direction of the reflected signal light beam is consistent with the light transmitting direction of the TO tube cap; the lens is arranged on the surface of the platform at the top of the reflector and is used for converging the reflected signal light beam; and the photodiode is arranged on one side of the laser, which is back to the reflecting mirror, and is used for detecting the optical power of the light beam emitted by the laser. This application sets up lens on the TO tube socket, has realized the optics high accuracy alignment of the relative laser instrument of lens through the speculum, has improved light path coupling efficiency greatly.

Description

Optical module

Technical Field

The application relates to the technical field of optical fiber communication, in particular to an optical module.

Background

The optical module is mainly used for photoelectric and electro-optical conversion, an electric signal is converted into an optical signal by a transmitting end of the optical module and is transmitted out through an optical fiber, and a received optical signal is converted into an electric signal by a receiving end of the optical module. The current packaging form of the optical module mainly includes a TO (Transistor-out) package and a COB (Chip on Board) package.

The core devices of the optical module are a laser LD and a photodiode PD, wherein the laser is used for converting an electric signal into an optical signal and coupling the optical signal into an optical fiber to realize signal transmission. The coupling efficiency is defined as the total light intensity of several percent emitted by the laser can be coupled into the optical fiber, and the coupling efficiency of the optical module package is very critical and directly influences the optical signal transmission performance and the production yield. In conventional coaxial TO packages, a lens is typically integrated into the TO cap, and the emitted light from the laser is converted into a converging light through the lens on the TO cap, coupling the laser into an optical fiber or other optical device.

However, in the coaxial TO packaging mode, when the TO pipe cap is welded on the TO pipe seat, the accuracy of a sealing welding machine can only be 30-50 um generally, a lens in the TO pipe cap and a laser in the TO pipe seat deviate after welding, the coaxiality of the lens and the laser cannot be guaranteed, and the coupling efficiency of a light path can be influenced.

Disclosure of Invention

The application provides an optical module TO solve the problem that the optical module of present TO encapsulation easily causes the fluctuation of light path coupling efficiency because of the sealing cap precision of TO pipe cap.

In order to solve the technical problem, the embodiment of the application discloses the following technical scheme:

the embodiment of the application discloses an optical module, includes:

a circuit board;

the light emitting device is electrically connected with the circuit board through a pin and is used for emitting a light beam;

wherein the light emitting device includes:

a TO header with a plurality of said pins;

the TO tube cap is covered on the TO tube seat, and a light-transmitting light window is arranged on the TO tube cap and used for transmitting the light beam;

the laser is arranged on the surface of the TO tube seat, is electrically connected with the pin and is used for emitting a signal beam, and the light emitting direction of the laser is not consistent with the light transmitting direction of the TO tube cap;

the reflecting mirror is provided with a bottom platform, a top platform and an inclined plane for connecting the bottom platform and the top platform, the bottom platform is fixed on the TO tube seat, and the inclined plane is used for reflecting the signal light beam from the laser so that the light emitting direction of the reflected signal light beam is consistent with the light transmitting direction of the TO tube cap;

the lens is arranged on the surface of the reflecting mirror top platform and used for converging the reflected signal light beam, so that the converged light beam is emitted out of the optical window of the TO pipe cap;

and the photodiode is arranged on one side of the laser back TO the reflector, is laterally fixed on the TO tube seat, is electrically connected with the pin and is used for detecting the optical power emitted by the laser.

The optical module provided by the application has the advantages that the lens of the light emitting device is arranged in the TO tube seat instead of being arranged on the TO tube cap, namely the TO tube cap and the lens are divided into two independent parts, and the lens is directly assembled on the TO tube seat, so that the lens and the laser are prevented from offsetting after being welded due TO poor sealing and welding precision of the TO tube cap; in addition, the light emitting direction of a signal beam emitted by a laser in the light emitting device is not consistent with the light transmitting direction of the TO pipe cap, and in order TO obtain the signal beam consistent with the light transmitting direction of the TO pipe cap, a reflector is arranged on a light path of the signal beam emitted by the laser and used for reflecting the signal beam from the laser, so that the light emitting direction of the reflected signal beam is consistent with the light transmitting direction of the TO pipe cap; the lens is arranged on the top surface of the reflector, so that the reflected light beams are totally emitted by the reflector and then enter the lens, and the reflected light beams are converged by the lens, for example, the reflected light beams can be directly converged and coupled into an external optical fiber or other optical devices, and can also be converted into collimated light beams. On TO tube socket was placed in with lens in this application, set up in the top of speculum, can carry out the accurate positioning TO lens according TO the reflection light path of speculum, realize the optics high accuracy alignment of the relative laser instrument of lens, and can not receive the influence of TO tube cap seal welding precision TO can improve the coupling efficiency of light path greatly.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic diagram of a connection relationship of an optical communication terminal;

fig. 2 is a schematic structural diagram of an optical network terminal;

fig. 3 is a schematic structural diagram of an optical module according to an embodiment of the present application;

fig. 4 is an exploded schematic structural diagram of an optical module according to an embodiment of the present disclosure;

fig. 5 is a structural diagram of a laser TO in the embodiment of the present application;

fig. 6 is an exploded view of a laser TO according TO an embodiment of the present disclosure;

FIG. 7 is an exploded view of another embodiment of the present application;

FIG. 8 is a partially exploded view of the laser TO according TO an embodiment of the present application;

fig. 9 is a schematic view of another partial structure of the laser TO in the embodiment of the present application;

FIG. 10 is a schematic view of another partially exploded structure of a laser TO according TO an embodiment of the present application;

FIG. 11 is a schematic view of the optical path of a single lens of the laser TO in an embodiment of the present application;

FIG. 12 is a schematic diagram of the optical path of a laser TO with two lenses according TO an embodiment of the present invention;

FIG. 13 is a schematic diagram of an exemplary optical path of a laser TO in an embodiment of the present application;

fig. 14 is another schematic optical path diagram of the laser TO in the embodiment of the present application.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

One of the core links of optical fiber communication is the interconversion of optical and electrical signals. The optical fiber communication uses optical signals carrying information to transmit in information transmission equipment such as optical fibers/optical waveguides, and the information transmission with low cost and low loss can be realized by using the passive transmission characteristic of light in the optical fibers/optical waveguides; meanwhile, the information processing device such as a computer uses an electric signal, and in order to establish information connection between the information transmission device such as an optical fiber or an optical waveguide and the information processing device such as a computer, it is necessary to perform interconversion between the electric signal and the optical signal.

The optical module realizes the function of interconversion of optical signals and electrical signals in the technical field of optical fiber communication, and the interconversion of the optical signals and the electrical signals is the core function of the optical module. The optical module is electrically connected with an external upper computer through a golden finger on an internal circuit board of the optical module, and the main electrical connection comprises power supply, I2C signals, data information, grounding and the like; the electrical connection mode realized by the gold finger has become the mainstream connection mode of the optical module industry, and on the basis of the mainstream connection mode, the definition of the pin on the gold finger forms various industry protocols/specifications.

Fig. 1 is a schematic diagram of connection relationship of an optical communication terminal. As shown in fig. 1, the connection of the optical communication terminal mainly includes interconnection among the optical network terminal 100, the optical module 200, the optical fiber 101, and the network cable 103.

One end of the optical fiber 101 is connected with a far-end server, one end of the network cable 103 is connected with local information processing equipment, and the connection between the local information processing equipment and the far-end server is completed by the connection between the optical fiber 101 and the network cable 103; and the connection between the optical fiber 101 and the network cable 103 is made by the optical network terminal 100 having the optical module 200.

An optical port of the optical module 200 is externally accessed to the optical fiber 101, and establishes bidirectional optical signal connection with the optical fiber 101; an electrical port of the optical module 200 is externally connected to the optical network terminal 100, and establishes bidirectional electrical signal connection with the optical network terminal 100; the optical module realizes the mutual conversion of optical signals and electric signals, thereby realizing the establishment of information connection between the optical fiber and the optical network terminal. Specifically, the optical signal from the optical fiber is converted into an electrical signal by the optical module and then input to the optical network terminal 100, and the electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module and input to the optical fiber.

The optical network terminal is provided with an optical module interface 102, which is used for accessing an optical module 200 and establishing bidirectional electric signal connection with the optical module 200; the optical network terminal is provided with a network cable interface 104, which is used for accessing the network cable 103 and establishing bidirectional electric signal connection with the network cable 103; the optical module 200 is connected to the network cable 103 via the optical network terminal 100. Specifically, the optical network terminal transmits a signal from the optical module to the network cable and transmits the signal from the network cable to the optical module, and the optical network terminal serves as an upper computer of the optical module to monitor the operation of the optical module.

At this point, a bidirectional signal transmission channel is established between the remote server and the local information processing device through the optical fiber, the optical module, the optical network terminal and the network cable.

Common information processing apparatuses include routers, switches, electronic computers, and the like; the optical network terminal is an upper computer of the optical module, provides data signals for the optical module, and receives the data signals from the optical module, and the common upper computer of the optical module also comprises an optical line terminal and the like.

Fig. 2 is a schematic diagram of an optical network terminal structure. As shown in fig. 2, the optical network terminal 100 has a circuit board 105, and a cage 106 is disposed on a surface of the circuit board 105; an electric connector is arranged in the cage 106 and used for connecting an electric port of an optical module such as a golden finger; the cage 106 is provided with a heat sink 107, and the heat sink 107 has a projection such as a fin that increases a heat radiation area.

The optical module 200 is inserted into the optical network terminal 100, specifically, an electrical port of the optical module is inserted into an electrical connector inside the cage 106, and an optical port of the optical module is connected to the optical fiber 101.

The cage 106 is positioned on the circuit board, and the electrical connector on the circuit board is wrapped in the cage, so that the electrical connector is arranged in the cage; the optical module is inserted into the cage, held by the cage, and the heat generated by the optical module is conducted to the cage 106 and then diffused by the heat sink 107 on the cage.

Fig. 3 is a schematic view of an optical module according to an embodiment of the present disclosure, and fig. 4 is a schematic view of an exploded structure of an optical module according to an embodiment of the present disclosure. As shown in fig. 3 and 4, an optical module 200 provided in the embodiment of the present application includes an upper housing 201, a lower housing 202, an unlocking member 203, a circuit board 300, and an optical transceiver 400.

The upper shell 201 is covered on the lower shell 202 to form a wrapping cavity with two openings; the outer contour of the packaging cavity generally presents a square body. Specifically, the lower housing 202 includes a main board and two side boards located at two sides of the main board and arranged perpendicular to the main board; the upper shell comprises a cover plate, and the cover plate covers two side plates of the upper shell to form a wrapping cavity; the upper shell may further include two side walls disposed at two sides of the cover plate and perpendicular to the cover plate, and the two side walls are combined with the two side plates to cover the upper shell 201 on the lower shell 202.

The two openings may be two ends (204, 205) in the same direction, or two openings in different directions; one opening is an electric port 204, and a gold finger of the circuit board extends out of the electric port 204 and is inserted into an upper computer such as an optical network terminal; the other opening is an optical port 205 for external optical fiber access to connect with the optical transceiver 400 inside the optical module; the photoelectric devices such as the circuit board 300 and the optical transceiver 400 are positioned in the packaging cavity.

The assembly mode of combining the upper shell and the lower shell is adopted, so that the circuit board 300, the optical transceiver 400 and other devices can be conveniently installed in the shells, and the upper shell and the lower shell form the outermost packaging protection shell of the module; the upper shell and the lower shell are made of metal materials generally, electromagnetic shielding and heat dissipation are achieved, the shell of the optical module cannot be made into an integral component generally, and therefore when devices such as a circuit board are assembled, the positioning component, the heat dissipation component and the electromagnetic shielding component cannot be installed, and production automation is not facilitated.

The unlocking component 203 is located on the outer wall of the wrapping cavity/lower shell 202, and is used for realizing the fixed connection between the optical module and the upper computer or releasing the fixed connection between the optical module and the upper computer.

The unlocking component 203 is provided with a clamping component matched with the upper computer cage; the end of the unlocking component can be pulled to enable the unlocking component to move relatively on the surface of the outer wall; the optical module is inserted into a cage of the upper computer, and the optical module is fixed in the cage of the upper computer by a clamping component of the unlocking component; by pulling the unlocking component, the clamping component of the unlocking component moves along with the unlocking component, so that the connection relation between the clamping component and the upper computer is changed, the clamping relation between the optical module and the upper computer is released, and the optical module can be drawn out from the cage of the upper computer.

The circuit board 300 is provided with circuit traces, electronic components (such as capacitors, resistors, triodes, and MOS transistors), and chips (such as an MCU, a laser driver chip, a limiting amplifier chip, a clock data recovery CDR, a power management chip, and a data processing chip DSP).

The circuit board 300 connects the electrical devices in the optical module together according to the circuit design through circuit wiring to realize the electrical functions of power supply, electrical signal transmission, grounding and the like.

The circuit board is generally a hard circuit board, and the hard circuit board can also realize a bearing effect due to the relatively hard material of the hard circuit board, for example, the hard circuit board can stably bear a chip; when the optical transceiver is positioned on the circuit board, the rigid circuit board can also provide stable bearing; the hard circuit board can also be inserted into an electric connector in the upper computer cage, and specifically, a metal pin/golden finger is formed on the surface of the tail end of one side of the hard circuit board and is used for being connected with the electric connector; these are not easily implemented with flexible circuit boards.

A flexible circuit board is also used in a part of the optical module to supplement a rigid circuit board; the flexible circuit board is generally used in combination with a rigid circuit board, for example, the rigid circuit board may be connected to the optical transceiver device through the flexible circuit board.

The optical transceiver comprises two parts, namely an optical transmitting device and an optical receiving device, which are respectively used for realizing the transmission of optical signals and the reception of the optical signals. The light emitting device generally comprises a light emitter, a lens and a light detector, wherein the lens and the light detector are respectively positioned on different sides of the light emitter, and the front side and the back side of the light emitter respectively emit light beams; the lens is used for converging the light beam emitted by the front surface of the light emitter, so that the light beam emitted by the light emitting device is converged light to be conveniently coupled to an external optical fiber; the optical detector is used for receiving the light beam emitted by the reverse side of the optical emitter so as to detect the optical power of the optical emitter. Specifically, light emitted by the light emitter enters the optical fiber after being converged by the lens, and the light detector detects the light emitting power of the light emitter so as to ensure the constancy of the light emitting power of the light emitter.

Fig. 5 is a schematic structural diagram of a light emitting device provided in an embodiment of the present application, and fig. 6 is an exploded schematic diagram of a light emitting device provided in an embodiment of the present application. As shown in fig. 5 and 6, the light emitting device is a coaxial TO package, the light emitter is a laser 4021, the light detector is a photodiode 4025, the optical fiber package further includes a TO tube holder 402 and a TO tube cap 401 for packaging the TO tube holder 402, the optoelectronic devices such as the laser 4021, the lens 4024, the photodiode 4025 and the like are placed on the surface of the TO tube holder 402, the TO tube cap 401 has a light window for light TO pass through, and the optoelectronic devices such as the laser 4021, the lens 4024, the photodiode 4025 and the like are packaged in the sealed cavity by the TO tube holder 402 and the TO tube cap 401.

The TO header 402 is provided with a plurality of pins 403, the pins 403 penetrate through the TO header 402 and protrude out of the surface of the TO header 402, and the pins 403 are wrapped by glass TO realize insulation between the pins 403 and the TO header 402. The optoelectronic device is sealed between the TO header 402 and the TO cap 401, which establishes electrical connection TO the outside by pins 403 passing through the TO header 402.

The laser 4021 comprises a laser chip and a laser ceramic heat sink 4022, the laser chip is welded on the laser ceramic heat sink 4022 by using gold-tin solder, and the laser ceramic heat sink 4022 is adhered on the TO tube seat 402 by using silver adhesive. After the laser 4021 is fixed on the TO tube holder 402, the positive and negative electrodes of the laser 4021 are electrically connected TO the corresponding pins 403 through gold wires (not shown) as needed, so as TO realize independent electrical connection between the positive electrode of the laser 4021 and the negative electrode of the laser and the outside.

In this example, the light emitting direction of the laser 4021 is not consistent with the light transmitting direction of the TO pipe cap 401, that is, the main optical axis of the signal beam emitted by the laser 4021 may be parallel TO the TO pipe seat 402, and the main optical axis of the signal beam transmitted by the TO pipe cap 401 may be perpendicular TO the TO pipe seat 402. In order TO enable the signal light beam TO pass through the TO pipe cap 401 and be coupled into the external optical fiber, a reflector 4023 is arranged on a light path of a light beam emitted by the laser 4021, the reflector 4023 is adhered TO the TO pipe seat 402 by glue and used for reflecting the signal light beam from the laser 4021, so that the light emitting direction of the reflected signal light beam is consistent with the light transmitting direction of the TO pipe cap 401, for example, the main optical axis of the reflected signal light beam is perpendicular TO the TO pipe cap 401 TO be coupled into the external optical fiber through the TO pipe cap 401. Glues include, but are not limited to, silver glue, UV glue, epoxy glue, UV epoxy glue, and the like.

The reflector 4023 is used TO provide a reflective surface for reflecting light so as TO change the transmission direction of the light beam emitted by the laser 4021, so that the signal light beam can still pass through the optical window of the TO cap 401 when the light emitting direction of the laser 4021 is not consistent with the light transmitting direction of the TO cap 401. In this example, the reflector 4023 is provided with a bottom platform, a top platform, and an inclined plane connecting the bottom platform and the top platform, the bottom platform is fixed on the surface of the TO tube seat 402, the top platform is parallel TO the surface of the TO tube seat 402, and the inclined plane is used for reflecting the signal beam from the laser 4021, so that the light emitting direction of the reflected signal beam is consistent with the light transmitting direction of the TO tube cap 401.

The reflector 4023 can be a reflection prism, and comprises a bottom platform, a top platform, three sides and an inclined plane, the bottom platform is pasted on the TO tube seat 402, the top platform is parallel TO the TO tube seat 402, three sides are perpendicular TO the TO tube seat 402, the inclined plane is connected with the top platform and the bottom platform, and the inclined plane is located on the transmitting direction of the laser 4021, a reflection film is plated on the inclined plane and used for reflecting the signal beam transmitted by the laser 4021, and the light emitting direction of the reflected signal beam is consistent with the light transmitting direction of the TO tube cap 401.

The reflector 4023 may also be composed of a bottom platform, a top platform, four sides and an inclined plane, the bottom platform is pasted on the TO tube seat 402, the top platform is parallel TO the TO tube seat 402, four sides are all perpendicular TO the TO tube seat 402, and a side is connected with the bottom platform and is close TO the light emitting surface of the laser 4021, the top platform and the bottom platform are connected respectively TO another three sides, the inclined plane is connected with the side of the top platform and is close TO the light emitting surface of the laser 4021, and the inclined plane is located on the transmitting direction of the laser 4021, a reflective film is plated on the inclined plane, and the reflective film is used for reflecting the signal beam transmitted by the laser 4021, so that the light emitting direction of the reflected signal beam is consistent with the light transmitting direction of the TO tube cap 401.

The reflector 4023 may also be composed of a bottom platform, a top platform, three sides and two slopes, the bottom platform is attached TO the TO tube seat 402, the top platform is parallel TO the TO tube seat 402, three sides are all perpendicular TO the TO tube seat 402, and one side is connected with the bottom platform and is close TO the light emitting surface of the laser 4021, the other two sides are connected with the top platform and the bottom platform respectively, one slope is connected with the top platform and the bottom platform, the other slope is connected with the top platform of the reflector 4023 and is close TO the side of the light emitting surface of the laser 4021, and the slope connecting the top platform and the side of the light emitting surface of the laser 4021 is located in the emitting direction of the laser 4021, a reflective film is plated on the slope for reflecting the signal beam emitted by the laser 4021, so that the light emitting direction of the reflected signal beam is consistent with the light transmitting direction of the TO tube cap 401.

The reflector 4023 may also include a base and a plane glass plated with a reflective film, the base is disposed on the surface of the TO tube seat 402, the base may include a bottom platform, a top platform, four sides and an inclined plane, the bottom platform of the base is adhered TO the TO tube seat 402, the top platform of the base is parallel TO the TO tube seat 402, the four sides are all perpendicular TO the TO tube seat 402, the inclined plane connects the top platform and one side of the base, and the inclined plane is located in the emitting direction of the laser 4021. The plane glass plated with the reflecting film is arranged on the inclined plane of the base and used for reflecting the signal beam emitted by the laser 4021, so that the light emitting direction of the reflected signal beam is consistent with the light transmitting direction of the TO pipe cap 401.

The flat glass may be adhered to the inclined surface of the base using glue including, but not limited to, silver glue, UV glue, epoxy glue, UV epoxy glue, etc.

The shape of the reflector provided in the embodiment of the present application is not limited TO the above shape, and as long as the shape satisfies the requirements of assembly and total reflection, the light emitting direction of the signal beam can be converted TO be consistent with the light transmitting direction of the TO cap 401, which all belong TO the protection scope of the embodiment of the present application.

The lens 4024 is disposed on the surface of the platform on the top of the reflector 4023, and is configured TO converge the reflected signal beam, so that the converged signal beam is emitted from the optical window of the TO cap 401, that is, divergent light emitted by the laser 4021 is reflected by the reflector 4023, so that the light emitting direction of the signal beam is converted into divergent light in accordance with the light transmitting direction of the TO cap 401, and then the divergent light is converged by the lens 4024 above the reflector 4023, for example, the reflected light beam is directly converged and coupled TO an external optical fiber, or is converted into a collimated light beam.

In this example, the lens 4024 is attached to the top platform of the reflector 4023 by glue, and the central axis of the lens 4024 may be perpendicular to the light emitting direction of the main optical axis of the laser 4021. In order to ensure accurate positioning of the lens, the positions of the reflector 4023 and the lens 4024 are determined by optical parameters of the lens, such as a focal length and a position of the laser 4021, and if the focal length of the lens 4024 is 1mm, the distance from the lens 4024 to the light emitting surface of the laser 4021 is 1mm, that is, the distance between the lens 4024 and a reflection point on the reflector 4023 plus the distance from the reflection point to the laser 4021 can be 1 mm; if the focal length of the lens 4024 is 0.5mm, the distance from the lens 4024 to the light emitting surface of the laser 4021 is 0.5mm, i.e., the distance from the lens 4024 to the reflection point on the mirror 4023 plus the distance from the reflection point to the laser 4021 may be 0.5 mm. Glues include, but are not limited to, silver glue, UV glue, epoxy glue, UV epoxy glue, and the like.

After the positions of the reflector 4023 and the lens 4024 are determined according to the focal length of the lens 4024 and the position of the laser 4021, the lens 4024 can be attached by a passive method, i.e., a high-precision chip mounter, or the lens 4024 and the laser 4021 can be aligned in a relative position by an active coupling method, and then the lens 4024 is fixed on a top platform of the reflector 4023 according to the determined position, so that the optical high-precision alignment of the lens 4024 relative to the laser 4021 is realized.

In this example, the lens 4024 is embedded in the TO stem 402 through the TO cap 401, and the distance between the lens 4024 and the laser 4021 is reduced, so that optical parameters such as the focal length of the lens 4024 can be reduced. Because the size of the laser spot is linearly increased along with the focal length of the lens, the laser spot passing through the lens 4024 is reduced under the condition that the focal length of the lens 4024 is reduced, the energy is more concentrated, and the laser coupling efficiency is improved.

The photodiode 4025 is provided on the side of the laser 4021 opposite to the mirror 4023, and is electrically connected to the pin 403. That is, the photodiode 4025 and the mirror 4023 are respectively located on both sides of the laser 4021, the mirror 4023 is located on the optical path of the light beam emitted from the front of the laser 4021, and the photodiode 4025 is located on the optical path of the light beam emitted from the back of the laser 4021. That is TO say, both opposite sides of the laser 4021 can emit light beams, and the light beams emitted from the front surface of the laser 4021 are reflected by the reflecting mirror 4023 and converted into light beams in the same direction as the light transmission direction of the TO cap 401, and then are converged by the lens 4024; and the light beam emitted from the back surface enters the photodiode 4025, and the optical power of the light beam emitted from the back surface of the laser 4021 is detected by the photodiode 4025, so that the optical power of the light beam emitted from the front surface of the laser 4021 is detected.

After the light power of light emitted by the front of the laser 4021 is detected, the laser 4021 can be dynamically adjusted, if the photodiode 4025 detects that the light power is increased, the light power emitted by the laser 4021 is increased, and the light emission of the laser 4021 is decreased by controlling a laser driving circuit to reduce the driving current applied to the laser; if the photodiode 4025 detects that the optical power becomes small, the optical power emitted by the laser 4021 becomes small, and the laser driving circuit is controlled to increase the driving current of the laser to reduce the light emission of the laser 4021, thereby ensuring the constant light emission power of the laser.

When the photodiode 4025 is mounted, the photodiode 4025 is adhered TO the PD ceramic heat sink 4026 by silver glue, the PD ceramic heat sink 4026 is adhered TO the TO socket 402 by glue on the side, and then the photodiode 4025 is electrically connected TO the pin 403 on the TO socket 402 by gold wire bonding, so as TO realize the optical power monitoring function of the photodiode 4025.

This application will originally set up the lens on TO pipe cap 401 and place in TO4 tube socket 402 on, for guaranteeing that the laser instrument is airtight encapsulation, can set up plane glass 404 in TO pipe cap 401's optical window department, this plane glass 404 is fixed through the glass solder with TO pipe cap 401's optical window TO the airtight encapsulation of TO pipe cap 401 with TO tube socket 402 spare has been realized. The flat glass 404 does not converge the signal light beam, that is, the light beam emitted from the lens 4024 directly passes through the flat glass 404 and does not converge the light beam.

That is, the signal beam emitted from the laser 4021 is reflected by the mirror 4023 and converted into a signal beam in accordance with the light transmission direction of the TO cap 401, the reflected signal beam is converted into a convergent light by the lens 4024, and the convergent light is directly coupled into an external optical fiber through the plane glass 404.

The Laser of the optical module is currently of two types, one is a Direct Modulated Laser (DML), and the other is an electro-absorption Modulated Laser (EML), which is an integrated device of an Electric Absorption Modulator (EAM) and a Distributed Feedback (DFB) Laser, and has better effect and larger power consumption than the DML. Compared with the DML, the EML is added with a refrigerator, a metal base, a thermistor (not labeled in the figure), a capacitor (not labeled in the figure), and the like.

Fig. 7 is a schematic structural diagram of another light emitting device provided in an embodiment of the present application, and fig. 8 is an exploded schematic diagram of another light emitting device provided in an embodiment of the present application. As shown in fig. 7 and 8, the light emitting device further includes a refrigerator 4027, and the refrigerator 4027 is attached TO the TO socket 402 by using silver paste, and is used for heat dissipation of optoelectronic devices such as the laser 4021 and the photodiode 4025. That is, the optoelectronic devices such as the laser 4021 and the photodiode 4025 are disposed on the refrigerator 4027, the photodiode 4025 is used as an active heat dissipation device, and heat generated by the optoelectronic devices such as the laser 4021 and the photodiode 4025 is transferred TO the TO socket 402 through the refrigerator 4027 TO dissipate heat.

In order to conveniently arrange photoelectric devices such as the laser 4021 and the photodiode 4025, a metal base 4028 is arranged on the refrigerator 4027, the metal base 4028 is adhered to the refrigerator 4027 by silver adhesive, and the photoelectric devices such as the laser 4021, the reflector 4023 and the photodiode 4025 are adhered to the metal base 4028 by glue. In this example, the metal base 4028 includes, but is not limited to, tungsten copper, raft alloy, SPCC (Steel Plate Cold rolled Commercial), copper, etc. to facilitate heat transfer from the optoelectronic device to the refrigerator 4027 for heat dissipation.

Fig. 9 is a partial schematic structural view of another light emitting device provided in an embodiment of the present application, and fig. 10 is a partial exploded schematic view of another light emitting device provided in an embodiment of the present application. As shown in fig. 9 and 10, a laser 4021 is soldered to a laser ceramic heatsink 4022 using gold-tin solder, and then the laser ceramic heatsink 4022 is horizontally attached to the surface of a metal base 4028 together with the laser 4021 using silver paste. Both opposite sides of the laser 4021 can emit light beams which are not consistent with the light transmission direction of the TO pipe cap 401, such as light beams with main optical axes parallel TO the TO pipe seat 402, a reflecting mirror 4023 is arranged on a light path of light beams emitted by the front surface of the laser 4021, the reflecting surface of the reflecting mirror 4023 corresponds TO the laser 4021 and is used for reflecting the light beams emitted by the laser 4021 into light beams which are consistent with the light transmission direction of the TO pipe cap 401, and the main optical axes of the reflected light beams are perpendicular TO the TO pipe seat 402.

The reflector 4023 is provided with a bottom platform, a top platform and an inclined plane 402-1 for connecting the bottom platform and the top platform, the bottom platform is fixed on the metal base 4028 by using glue, and the inclined plane 402-1 is used for reflecting a signal beam from the laser 4021, so that the light emitting direction of the reflected signal beam is consistent with the light transmitting direction of the TO pipe cap 401.

The lens 4024 is attached to the top platform of the reflector 4023 by glue, and the light beam reflected by the reflector 4023 enters the lens 4024 to converge the reflected light beam through the lens 4024.

A photodiode 4025 is arranged on a light path of a light beam emitted from the back surface of the laser 4021, the photodiode 4025 is attached to the PD ceramic heat sink 4026 by silver glue, and the PD ceramic heat sink 4026 side is immediately attached to the metal base 4028 by glue for detecting the optical power of the light beam emitted from the back surface of the laser 4021.

The laser 4021 and the photodiode 4025 fixed on the metal base 4028 are connected with corresponding pins 403 on the TO tube seat 402 by gold wire bonding, so that the anode of the laser and the cathode of the laser are independently and electrically connected with the outside, and the photodiode 4025 is electrically connected with the outside.

The signal beam which is not in accordance with the light transmission direction of the TO cap 401 and is reflected by the mirror 4023 and converted into a signal beam in accordance with the light transmission direction of the TO cap 401, and the reflected signal beam is converged by the lens 4024, which is attached TO the metal base 4028.

Fig. 11 is a schematic diagram of an optical path of an emitted light beam of a laser according to an embodiment of the present application. As shown in fig. 11, the lens 4024 may be a point-TO-point converging lens, the laser 4021 emits a signal beam that is not in line with the light transmission direction of the TO pipe cap 401, for example, emits a signal beam whose principal axis is parallel TO the TO pipe seat 402, the signal beam is reflected by the mirror 4023 and converted into a signal beam whose principal axis is perpendicular TO the TO pipe seat 402, the reflected signal beam is converted into a converging light by the point-TO-point converging lens, and the converging light is coupled into the external optical fiber 101 through the plane glass 404, so as TO achieve the purpose of coupling laser light TO the optical fiber.

Fig. 12 is a schematic diagram of an optical path of an emission beam of another laser according to an embodiment of the present disclosure. As shown in fig. 12, the lens 4024 can also be a collimating lens, and then a corresponding converging lens 500 can be placed between the TO cap 401 and the external fiber 101. Thus, the laser 4021 emits a signal light beam with a main optical axis parallel TO the TO header 402, the signal light beam is converted into a signal light beam with a main optical axis perpendicular TO the TO header 402 after being reflected by the reflector 4023, the reflected signal light beam is converted into a collimated light beam through the collimating lens, the collimated light beam penetrates through the plane glass 404, the collimated light beam is converted into a convergent light beam through the convergent lens 500, and the convergent light beam is coupled into the external optical fiber 101, so that the purpose of coupling laser TO the optical fiber is achieved.

In this example, the lens 4024 is mainly made of glass, silicon, plastic PEI, or the like.

The reflector 4023 is configured TO receive a signal beam emitted from the laser 4021 and having a direction different from the light transmission direction of the TO cap 401, and convert the signal beam into a beam having a direction corresponding TO the light transmission direction of the TO cap 401. Fig. 13 is a schematic diagram of an exemplary optical path provided in an embodiment of the present application. As shown in fig. 13, the light emitting direction of the main optical axis of the laser 4021 may be perpendicular TO the central axis of the TO stem 402, the reflector 4023 may be a 45-degree reflecting prism, and when the signal beam emitted by the laser 4021 is transmitted TO the reflecting surface of the reflector 4023, the signal beam is reflected by 45 degrees, so that the horizontal beam is converted into a reflected beam perpendicular TO the TO stem 402.

Fig. 14 is another schematic optical path diagram provided in the embodiment of the present application. As shown in fig. 14, the light emitting direction of the main optical axis of the laser 4021 may also form a preset angle with the central axis of the TO stem 402, the angle between the reflector 4023 and the central axis of the TO stem 402 is not 45 degrees, for example, the angle between the reflector 4023 and the central axis of the TO stem 402 is 44 degrees or 46 degrees, and the main optical axis of the laser 4021 is perpendicular TO the TO stem 402 after being reflected by the reflector 4023 as long as the light emitting direction of the laser 4021 is rotated by a matching angle according TO the reflection principle during assembly.

The angle between the reflector 4023 and the laser 4021 provided by the embodiment of the present application is not limited TO the angle described in the above embodiments, as long as the angle between the reflection surface of the reflector 4023 and the light emitting direction of the laser is a matching angle, the reflector 4023 can reflect the light beam emitted by the laser 4021 into a light beam consistent with the light transmitting direction of the TO cap 401, and both belong TO the protection scope of the embodiment of the present application.

The light emitting device in the optical module provided by the embodiment of the application adopts TO encapsulation, and comprises a TO tube seat and a TO tube cap used for encapsulating the TO tube seat, wherein photoelectric devices such as a laser, a reflector, a lens, a photodiode and the like are placed on the surface of the TO tube seat, a plurality of pins are arranged on the TO tube seat, and the anode and the cathode of the laser are electrically connected with corresponding pins on the TO tube seat in a gold wire bonding mode respectively so as TO generate signal beams with different light transmission directions from the TO tube cap; the reflector is arranged on a light path of the signal light beam generated by the front surface of the laser and used for reflecting the signal light beam from the laser so as TO convert the signal light beam which is not consistent with the light transmission direction of the TO pipe cap into the signal light beam which is consistent with the light transmission direction of the TO pipe cap; the lens is arranged above the reflector and used for converging the reflected signal light beam, and the coaxiality of the reflecting point of the lens and the reflector is ensured according to the reflection principle, so that the optical high-precision alignment of the lens relative to the laser is realized, and the coupling efficiency is improved; the photodiode is arranged on a light path of a signal light beam emitted by the back of the laser, is electrically connected with a corresponding pin on the TO tube seat in a gold wire bonding mode TO detect the light power of the light beam emitted by the laser, and can dynamically adjust the laser according TO the detected light power of the laser TO ensure the constancy of the light emitting power of the laser; the optical window department of TO pipe cap is provided with the flat window glass, and TO pipe cap and TO tube socket carry out the electric capacity and weld in order TO realize airtight encapsulation, have satisfied the reliability demand of laser instrument.

The embodiment of the application provides a laser light path of a light emitting device in an optical module can be: the laser emits a signal light beam with a main optical axis parallel TO the TO tube seat, the signal light beam is converted into a signal light beam with the main optical axis perpendicular TO the TO tube seat through the reflector, the reflected signal light beam is converted into convergent light through the convergent lens, the convergent light penetrates through the flat window glass and is coupled into an external optical fiber in a convergent mode, and the purpose of coupling laser into the optical fiber is achieved.

The optical module that this application embodiment provided places the TO tube socket in with lens in, for with lens setting on the TO pipe cap, so reduced the distance of laser instrument and lens, reduced the focus of lens, improved coupling efficiency, and solved the poor light path skew that causes of traditional TO pipe cap seal-weld precision, it is undulant TO have reduced optic fibre coupling efficiency, has further improved coupling efficiency.

It should be noted that, in the present specification, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a circuit structure, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such circuit structure, article, or apparatus. Without further limitation, the presence of an element identified by the phrase "comprising an … …" does not exclude the presence of other like elements in a circuit structure, article or device comprising the element.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

The above-described embodiments of the present application do not limit the scope of the present application.

Claims

1. A light module, comprising:

a circuit board;

wherein the light emitting device includes:

a TO header with a plurality of said pins;

2. The optical module of claim 1, wherein the reflector further comprises a side surface adjacent to the light emitting surface of the laser, the side surface is connected to the bottom platform and the inclined surface respectively, and the side surface is perpendicular to the bottom platform.

3. The optical module of claim 1, wherein the reflector comprises a base and a reflective film coated flat glass, the base being disposed on a surface of the TO header; the plane glass plated with the reflecting film is arranged on the inclined plane of the base and used for reflecting the light beam emitted by the laser to the lens.

4. The optical module of claim 1, wherein the relative distance of the lens from the laser is a focal length of the lens.

5. The optical module of claim 4, wherein the lens is a converging lens for converging and coupling the reflected signal beam to an external optical fiber.

6. The optical module of claim 4, wherein the lens is a collimating lens for converting the reflected signal beam into a collimated beam.

7. The optical module of claim 1, wherein a central axis of the laser and a central axis of the TO tube seat form a predetermined angle, and an angle of the reflecting surface of the reflector matches with the central axis of the laser, so that a light emitting direction of a light beam emitted by the laser is consistent with a light transmitting direction of the TO tube cap after being reflected by the reflector.

8. The optical module as claimed in claim 1, wherein a plane glass is disposed at the optical window, and the light beam emitted from the lens directly transmits through the plane glass.

9. A light module, comprising: a circuit board;

wherein the light emitting device includes:

a TO header with a plurality of said pins;

a refrigerator disposed on a surface of the TO header for adjusting heat of the light emitting device;

a metal base disposed on a surface of the refrigerator;

the laser is arranged on the surface of the metal base, is electrically connected with the pin and is used for emitting a signal beam, and the light emitting direction of the laser is not consistent with the light transmitting direction of the TO tube cap;

the reflecting mirror is provided with a bottom platform, a top platform and an inclined plane for connecting the bottom platform and the top platform, the bottom platform is fixed on the metal base, and the inclined plane is used for reflecting the signal beam from the laser so that the light emitting direction of the reflected signal beam is consistent with the light transmitting direction of the TO pipe cap;

the lens is arranged on the surface of the reflecting mirror top platform and used for converging the reflected signal light beam, so that the converged light beam is emitted out through the optical window of the TO pipe cap;

and the photodiode is arranged on one side of the laser back to the reflector, is laterally fixed on the metal base, is electrically connected with the pin, and is used for detecting the optical power emitted by the laser.

10. The optical module according to claim 9, wherein the reflector includes a base and a flat glass plated with a reflective film, the base being disposed on a surface of the metal base; the plane glass plated with the reflecting film is arranged on the inclined plane of the base and used for reflecting the light beam emitted by the laser to the lens.