WO2021212850A1

WO2021212850A1 - Optical module

Info

Publication number: WO2021212850A1
Application number: PCT/CN2020/133902
Authority: WO
Inventors: 邵乾; 刘维伟; 张占鹏; 任乐燕
Original assignee: 青岛海信宽带多媒体技术有限公司
Priority date: 2020-04-21
Filing date: 2020-12-04
Publication date: 2021-10-28

Abstract

An optical module (200), comprising: a circuit board (300) and a light-emitting component. The light-emitting component comprises: a TO transistor base (402); a TO transistor cap (401), covering the TO transistor base (402); a laser (4021), provided on the surface of the TO transistor base (402), used for emitting a signal light beam, and the direction of light emission of the laser (4021) being inconsistent with the direction of light transmission of the TO transistor cap (401); a mirror (4023), provided with a bottom platform, a top platform, and an oblique surface, the bottom platform being fixed on the TO transistor base (402), and the oblique surface being used for reflecting the signal light beam from the laser (4021) so that the direction of light emission of the reflected signal light beam is consistent with the direction of light transmission of the TO transistor cap (401); a lens (4024), provided on the surface of the top platform of the mirror (4023) and used for converging the reflected signal light beam; and a photodiode (4025), provided on the side of the laser (4021) facing away from the mirror (4023) and used for detecting the optical power of a light beam emitted by the laser (4021). With the lens (4024) being provided on the TO transistor base (402), implemented via the mirror (4023) is the optically high-precision alignment of the lens (4024) relative to the laser (4021), thus increasing the efficiency of optical path coupling.

Description

An optical module

This disclosure requires that it be submitted to the Chinese Patent Office on April 21, 2020, the application number is 202010317416.1, the name of the invention is "a kind of optical module", and it is submitted to the Chinese Patent Office on April 21, 2020, the application number is 202020608847.9, and the patent name is The priority of "a kind of optical module", the entire content of which is incorporated in the present disclosure by reference.

Technical field

The present disclosure relates to the field of optical communication technology, and in particular to an optical module.

Background technique

The optical module is mainly used for photoelectric and electro-optical conversion. The transmitting end converts the electrical signal into an optical signal and transmits it through the optical fiber, and the receiving end converts the received optical signal into an electrical signal. At present, the packaging forms of optical modules mainly include TO (Transistor-Outline, coaxial) packaging and COB (Chip on Board) packaging.

The core components of the optical module are the laser LD and the photodiode PD. Among them, the function of the laser is to convert electrical signals into optical signals, and the optical signals can be coupled into the optical fiber to realize signal transmission. A few percent of the total light intensity emitted by the laser can be coupled into the fiber as the coupling efficiency. The coupling efficiency of the optical module package is very critical, which directly affects the optical signal transmission performance and production yield. In the traditional coaxial TO package, the lens is usually integrated in the TO cap. The emitted light from the laser is converted to convergent light through the lens on the TO cap, and the laser is coupled to the optical fiber or other optical devices.

However, with this coaxial TO packaging method, when the TO cap is welded to the TO base, the accuracy of the sealing machine can only be 30-50um. The lens in the TO cap and the laser in the TO base are in There is an offset after welding, and it is impossible to ensure that the lens and the laser are coaxial, which will affect the coupling efficiency of the optical path.

Summary of the invention

The embodiment of the present disclosure discloses an optical module, including: a circuit board; a light emitting device, which is electrically connected to the circuit board through pins, for emitting light; wherein, the light emitting device includes: a TO tube holder with a plurality of tubes Foot; TO tube cap, which is set on the TO tube base, and a light window is provided on the TO tube cap to transmit the light beam; the laser is set on the surface of the TO tube base and is electrically connected to the pin, It is used to emit signal beams, and the direction of laser light is inconsistent with the direction of light transmission of the TO tube cap; the reflector is provided with a bottom platform, a top platform, and an inclined plane connecting the bottom platform and the top platform, and the bottom platform is fixed on the TO tube seat. The inclined surface is used to reflect the signal beam from the laser, so that the direction of the reflected signal beam is consistent with the transmission direction of the TO cap; the lens is set on the surface of the top platform of the reflector to converge the reflected signal beam , Which makes the converged beam emitted from the light window of the TO tube cap; the photodiode is arranged on the side of the laser facing away from the reflector, fixed laterally on the TO tube socket, and electrically connected to the pin, used to detect the laser emitting beam The optical power.

Description of the drawings

In order to explain the technical solutions of the present disclosure more clearly, the following will briefly introduce the drawings needed in the embodiments. Obviously, for those of ordinary skill in the art, without creative labor, Other drawings can also be obtained from these drawings.

Figure 1 is a schematic diagram of the connection relationship of an optical communication terminal;

Figure 2 is a schematic diagram of the optical network terminal structure;

FIG. 3 is a schematic structural diagram of an optical module provided by an embodiment of the disclosure;

4 is a schematic diagram of an exploded structure of an optical module provided by an embodiment of the disclosure;

FIG. 5 is a structural diagram of a laser TO in an embodiment of the disclosure;

FIG. 6 is a schematic diagram of an exploded structure of a laser TO in an embodiment of the disclosure;

FIG. 7 is a schematic diagram of an exploded structure of another laser TO in an embodiment of the disclosure;

FIG. 8 is a schematic diagram of a partial decomposition structure of the laser TO in an embodiment of the disclosure;

FIG. 9 is a schematic diagram of another partial structure of the laser TO in an embodiment of the disclosure;

FIG. 10 is a schematic diagram of another partial decomposition structure of the laser TO in an embodiment of the disclosure;

FIG. 11 is a schematic diagram of a single lens optical path of a laser TO in an embodiment of the disclosure;

FIG. 12 is a schematic diagram of the optical path of the double lens of the laser TO in the embodiment of the disclosure;

FIG. 13 is a schematic diagram of a typical optical path of a laser TO in an embodiment of the disclosure;

FIG. 14 is a schematic diagram of another optical path of the laser TO in an embodiment of the disclosure.

Detailed ways

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present disclosure.

One of the core links of optical fiber communication is the mutual conversion of optical and electrical signals. Optical fiber communication uses information-carrying optical signals to be transmitted in optical fibers/optical waveguides and other information transmission equipment. The passive transmission characteristics of light in optical fibers/optical waveguides can achieve low-cost and low-loss information transmission; and computers and other information processing equipment Electrical signals are used. In order to establish an information connection between information transmission equipment such as optical fibers/optical waveguides and information processing equipment such as computers, it is necessary to realize mutual conversion between electrical signals and optical signals.

The optical module realizes the above-mentioned mutual conversion function of optical and electrical signals in the field of optical fiber communication technology, and the mutual conversion of optical signals and electrical signals is the core function of the optical module. The optical module realizes the electrical connection with the external host computer through the golden finger on its internal circuit board. The main electrical connections include power supply, I2C signal, data information and grounding, etc.; the electrical connection method realized by the golden finger has become the optical module The mainstream connection method of the industry, based on this, the definition of the pins on the golden finger has formed a variety of industry protocols/standards.

Figure 1 is a schematic diagram of the connection relationship of an optical communication terminal. As shown in FIG. 1, the connection of the optical communication terminal mainly includes the interconnection between 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 to the remote server, and one end of the network cable 103 is connected to the local information processing equipment. The connection between the local information processing equipment and the remote server is completed by the connection of the optical fiber 101 and the network cable 103; and the connection between the optical fiber 101 and the network cable 103 is The optical network terminal 100 with the optical module 200 is completed.

The optical port of the optical module 200 is externally connected to the optical fiber 101 to establish a bidirectional optical signal connection with the optical fiber 101; the electrical port of the optical module 200 is externally connected to the optical network terminal 100 to establish a bidirectional electrical signal connection with the optical network terminal 100; The optical module realizes the mutual conversion between the optical signal and the electrical signal, so as to realize the establishment of an information connection between the optical fiber and the optical network terminal. In an embodiment of the present disclosure, the optical signal from the optical fiber is converted into an electrical signal by the optical module and then input into 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 into the optical fiber. .

The optical network terminal has an optical module interface 102, which is used to connect to the optical module 200 and establish a two-way electrical signal connection with the optical module 200; the optical network terminal has a network cable interface 104, which is used to connect to the network cable 103 and establish a two-way electrical connection with the network cable 103 Signal connection; a connection is established between the optical module 200 and the network cable 103 through the optical network terminal 100. In an embodiment of the present disclosure, the optical network terminal transmits the 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 acts as the upper computer of the optical module to monitor the operation of the optical module.

So far, the remote server establishes a two-way signal transmission channel with the local information processing equipment through optical fibers, optical modules, optical network terminals and network cables.

Common information processing equipment includes routers, switches, electronic computers, etc.; the optical network terminal is the upper computer of the optical module, which provides data signals to the optical module and receives data signals from the optical module. The common optical module upper computer also has optical lines Terminal and so on.

Figure 2 is a schematic diagram of the optical network terminal structure. As shown in Figure 2, the optical network terminal 100 has a circuit board 105, and a cage 106 is provided on the surface of the circuit board 105; an electrical connector is provided inside the cage 106 for accessing optical module electrical ports such as golden fingers; A heat sink 107 is provided on the cage 106, and the heat sink 107 has protrusions such as fins that increase the heat dissipation area.

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

The cage 106 is located on the circuit board and wraps the electrical connector on the circuit board in the cage, so that the electrical connector is arranged inside the cage; the optical module is inserted into the cage, and the optical module is fixed by the cage, and the heat generated by the optical module is conducted to the cage 106, and then spread through the radiator 107 on the cage.

FIG. 3 is a schematic structural diagram of an optical module provided by an embodiment of the present disclosure, and FIG. 4 is a schematic diagram of an exploded structure of an optical module provided by an embodiment of the present disclosure. As shown in FIG. 3 and FIG. 4, the optical module 200 provided by the embodiment of the present disclosure includes an upper housing 201, a lower housing 202, an unlocking component 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 wrapping cavity generally presents a square shape. In an embodiment of the present disclosure, the lower housing 202 includes a main board and two side plates located on both sides of the main board and arranged perpendicular to the main board; The side plate is used to form a wrapping cavity; the upper housing may also include two side walls located on both sides of the cover plate and perpendicular to the cover plate. The two side walls are combined with the two side plates to realize the upper housing 201 is covered on the lower housing 202.

The two openings can be two openings (204, 205) in the same direction, or two openings in different directions; one of the openings is the electrical port 204, and the gold finger of the circuit board protrudes from the electrical port 204 , Inserted into an upper computer such as an optical network terminal; the other opening is an optical port 205, which is used for external optical fiber access to connect the optical transceiver device 400 inside the optical module; the circuit board 300, optical transceiver device 400 and other optoelectronic devices are located in the package cavity middle.

The assembly method of the upper shell and the lower shell is used to facilitate the installation of the circuit board 300, the optical transceiver device 400 and other components into the shell. The upper shell and the lower shell form the outermost package protection shell of the module; The upper shell and the lower shell generally use metal materials to realize electromagnetic shielding and heat dissipation. Generally, the shell of the optical module is not made into an integral part, so that when assembling circuit boards and other devices, positioning parts, heat dissipation and electromagnetic shielding parts Unable to install, it is not conducive to production automation.

The unlocking component 203 is located on the outer wall of the wrapping cavity/lower casing 202, and is used to realize a fixed connection between the optical module and the upper computer, or to release the fixed connection between the optical module and the upper computer.

The unlocking component 203 has an engaging component that matches the cage of the host computer; pulling the end of the unlocking component can make the unlocking component move relatively on the surface of the outer wall; the optical module is inserted into the cage of the host computer, and the optical module is held by the engaging component of the unlocking component Fixed in the cage of the host computer; by pulling the unlocking part, the locking part of the unlocking part moves accordingly, and then the connection relationship between the locking part and the host computer is changed, so as to release the optical module and the host computer. The optical module is withdrawn from the cage of the host computer.

The circuit board 300 is provided with circuit wiring, electronic components (such as capacitors, resistors, transistors, MOS tubes) and chips (such as MCUs, laser drive chips, limiting amplification chips, clock data recovery CDR, power management chips, and data processing chips) DSP) and so on.

The circuit board 300 connects the electrical components in the optical module according to the circuit design through circuit wiring to achieve electrical functions such as power supply, electrical signal transmission, and grounding.

The circuit board is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the carrying function. For example, the rigid circuit board can carry the chip smoothly; when the optical transceiver is on the circuit board, the rigid circuit board can also provide Stable bearing; the rigid circuit board can also be inserted into the electrical connector in the upper computer cage. In an embodiment of the present disclosure, a metal pin/gold finger is formed on the end surface of one side of the rigid circuit board for the electrical connection Connector connection; these are inconvenient for flexible circuit boards.

Some optical modules also use flexible circuit boards as a supplement to rigid circuit boards; flexible circuit boards are generally used in conjunction with rigid circuit boards, for example, flexible circuit boards can be used to connect between rigid circuit boards and optical transceiver devices.

The optical transceiver device includes two parts: a light emitting device and a light receiving device, which are respectively used to realize the transmission of optical signals and the reception of optical signals. The light emitting device generally includes a light emitter, a lens and a light detector, and the lens and the light detector are respectively located on different sides of the light emitter, and the front and back sides of the light emitter emit light beams respectively; the lens is used to converge the front of the light emitter The emitted light beam makes the light beam emitted by the light emitting device convergent light to facilitate coupling to an external optical fiber; the light detector is used to receive the light beam emitted from the opposite side of the light emitter to detect the optical power of the light emitter. In an embodiment of the present disclosure, the light emitted by the light emitter enters the optical fiber after being condensed by the lens, and the light detector detects the luminous power of the light emitter to ensure the constancy of the light power emitted by the light emitter.

FIG. 5 is a schematic structural diagram of a light emitting device provided by an embodiment of the disclosure, and FIG. 6 is an exploded schematic diagram of a light emitting device provided by an embodiment of the disclosure. As shown in Fig. 5 and Fig. 6, the light emitting device adopts a coaxial TO package, the light emitter is a laser 4021, and the photodetector is a photodiode 4025. It also includes a TO tube holder 402 and a TO tube for packaging the TO tube holder 402. The cap 401, the laser 4021, the lens 4024, and the photodiode 4025 are placed on the surface of the TO tube holder 402. The TO tube cap 401 has a light window for light transmission. The TO tube holder 402 and the TO tube cap 401 connect the laser Optoelectronic devices such as 4021, lens 4024, and photodiode 4025 are encapsulated in a sealed cavity.

The TO socket 402 has a plurality of pins 403, the pins 403 pass through the TO socket 402 and protrude from the surface of the TO socket 402, and the pins 403 are wrapped by glass to realize the gap between the pins 403 and the TO socket 402. Insulation. The optoelectronic device is sealed between the TO base 402 and the TO cap 401, and establishes an electrical connection with the outside through the pin 403 passing through the TO base 402.

The laser 4021 includes a laser chip and a laser ceramic heat sink 4022. The laser chip is soldered on the laser ceramic heat sink 4022 using gold-tin solder, and the laser ceramic heat sink 4022 is pasted on the TO tube socket 402 using silver glue. After the laser 4021 is fixed on the TO tube holder 402, its positive and negative poles are electrically connected to the corresponding pins 403 through gold wires (not shown in the figure) as needed to realize the separate electrical connection of the laser 4021 positive pole and the laser negative pole to the outside.

In this example, the light emission direction of the laser 4021 is not consistent with the light transmission direction of the TO cap 401, that is, the main optical axis of the signal beam emitted by the laser 4021 can be parallel to the TO base 402, and the signal beam transmitted by the TO cap 401 The main optical axis may be perpendicular to the TO tube socket 402. In order to make the signal beam pass through the TO tube cap 401 and be coupled to the external optical fiber, a mirror 4023 is provided on the optical path of the laser 4021 emitting beam, and the mirror 4023 is glued on the TO tube holder 402 to reflect from the laser 4021. The signal beam makes the direction of the reflected signal beam consistent with the transmission direction of the TO cap 401. For example, the main optical axis of the reflected signal beam is perpendicular to the TO cap 401 to couple to the external optical fiber through the TO cap 401 middle. Glues include but are not limited to silver glue, UV glue, epoxy glue, UV epoxy glue, etc.

The reflector 4023 is used to provide a reflective surface for light reflection to change the transmission direction of the beam emitted by the laser 4021, so that the signal beam can still be transmitted by the TO when the light output direction of the laser 4021 is inconsistent with the light transmission direction of the TO cap 401 The light window of the cap 401 passes through. In this example, the reflector 4023 is provided with a bottom platform, a top platform, and a slope connecting the bottom platform and the top platform. The bottom platform is fixed on the surface of the TO tube socket 402, and the top platform is parallel to the surface of the TO tube socket 402. In order to reflect the signal beam from the laser 4021, the light emitting direction of the reflected signal beam is consistent with the light transmission direction of the TO cap 401.

The reflector 4023 can be a reflecting prism, which is composed of a bottom platform, a top platform, three sides and an inclined plane. The bottom platform is pasted on the TO tube base 402, the top platform is parallel to the TO tube base 402, and the three sides are perpendicular to the TO tube base 402. TO tube holder 402, the inclined surface is connected to the top platform and the bottom platform, and the inclined surface is located in the emitting direction of the laser 4021. The inclined surface is plated with a reflective film for reflecting the signal beam emitted by the laser 4021, so that the reflected signal beam is emitted The direction is consistent with the light transmission direction of the TO cap 401.

The reflector 4023 can 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 base 402, the top platform is parallel to the TO tube base 402, and the four sides are perpendicular to the TO tube base 402. , And one side is connected to the bottom platform and is close to the emitting surface of the laser 4021, the other three sides are respectively connected to the top platform and the bottom platform, and the slope connects the top platform and the side close to the emitting surface of the laser 4021, and the slope is located in the emitting direction of the laser 4021 A reflective film is plated on the inclined surface to reflect the signal beam emitted by the laser 4021, so that the light exit direction of the reflected signal beam is consistent with the light transmission direction of the TO cap 401.

The reflector 4023 can also be composed of a bottom platform, a top platform, three sides and two inclined surfaces. The bottom platform is pasted on the TO tube base 402, the top platform is parallel to the TO tube base 402, and the three sides are all perpendicular to the TO tube base. 402, and one side is connected to the bottom platform and close to the light-emitting surface of the laser 4021, the other two sides are connected to the top platform and the bottom platform, one slope connects the top platform and the bottom platform, and the other slope connects the top platform of the mirror 4023 and close to the laser The side surface of the 4021 emitting surface, and the inclined surface connecting the top platform and the side surface close to the emitting surface of the laser 4021 is located in the emitting direction of the laser 4021. The light emission direction of the signal beam is consistent with the light transmission direction of the TO cap 401.

The reflector 4023 can also include a base and a flat glass plated with a reflective film. The base is set on the surface of the TO tube base 402. The base can be composed of a bottom platform, a top platform, four sides and an inclined surface. The bottom platform of the base is glued. On the TO tube base 402, the top platform of the base is parallel to the TO tube base 402, and the four sides are perpendicular to the TO tube base 402. The inclined plane connects the top platform of the base with one side surface, and the inclined plane is located in the emitting direction of the laser 4021. The plane glass coated with a reflective film is arranged on the inclined surface of the base to reflect the signal beam emitted by the laser 4021 so that the light emission direction of the reflected signal beam is consistent with the light transmission direction of the TO cap 401.

The flat glass can be pasted on the inclined surface of the base using glue. The glue includes, but is not limited to, silver glue, UV glue, epoxy glue, UV epoxy glue, and the like.

The shape of the reflector provided by the embodiment of the present disclosure is not limited to the above-mentioned shape, as long as it satisfies assembly and total reflection, and can convert the light emission direction of the signal beam to be consistent with the light transmission direction of the TO cap 401, all of which belong to the present disclosure The scope of protection of the embodiment.

The lens 4024 is arranged on the surface of the top platform of the reflector 4023 and is used to converge the reflected signal beam so that the converged beam is emitted from the light window of the TO cap 401, that is, the divergent light emitted by the laser 4021 passes through The reflector 4023 reflects, so that the exit direction of the signal beam is converted into divergent light consistent with the transmission direction of the TO cap 401, and then the divergent light is condensed through the lens 4024 above the reflector 4023, such as directly converging and coupling the reflected beam To an external fiber, or convert it into a collimated beam.

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

After determining the position of the mirror 4023 and the lens 4024 according to the focal length of the lens 4024 and the position of the laser 4021, the lens 4024 can be mounted passively, that is, by using a high-precision mounter, or through active coupling. The lens 4024 is aligned with the relative position of the laser 4021, and then the lens 4024 is fixed on the top platform of the reflector 4023 according to the determined position, so as to realize the optical high-precision alignment of the lens 4024 with the laser 4021.

In this example, the lens 4024 is built into the TO tube holder 402 with the TO tube cap 401, which reduces the distance between the lens 4024 and the laser 4021, so that optical parameters such as the focal length of the lens 4024 can be reduced. Since the size of the laser spot increases linearly with the focal length of the lens, when the focal length of the lens 4024 decreases, the laser spot passing through the lens 4024 is also reduced, and the energy is more concentrated, thereby improving the laser coupling efficiency.

The photodiode 4025 is arranged on the side of the laser 4021 facing away from the reflector 4023, and is electrically connected to the pin 403. That is, the photodiode 4025 and the reflector 4023 are respectively located on both sides of the laser 4021, the reflector 4023 is located on the optical path of the beam emitted from the front of the laser 4021, and the photodiode 4025 is located on the optical path of the beam emitted from the back of the laser 4021. That is to say, the two opposite sides of the laser 4021 can emit light beams, and the light beam emitted from the front side is reflected by the reflector 4023 and converted into a light beam consistent with the light transmission direction of the TO cap 401, and then converged by the lens 4024; The light beam emitted from the back enters the photodiode 4025. The photodiode 4025 detects the optical power of the beam emitted from the back of the laser 4021, thereby detecting the optical power of the beam emitted from the front of the laser 4021.

After detecting the optical power of the beam emitted from the front of the laser 4021, the laser 4021 can be dynamically adjusted. If the photodiode 4025 detects that the optical power becomes larger, the laser 4021 emits a larger optical power, which can be reduced by controlling the laser drive circuit. The drive current to the laser makes the laser 4021 emit smaller light; if the photodiode 4025 detects that the optical power becomes smaller, the laser 4021 emits lower optical power. The laser drive circuit can be controlled to increase the drive current of the laser to make the laser 4021 smaller. The luminescence becomes smaller, so as to ensure the constant luminous power of the laser.

When installing the photodiode 4025, the photodiode 4025 is pasted on the PD ceramic heat sink 4026 with silver glue, and the PD ceramic heat sink 4026 is pasted on the TO base 402 with glue, and then the photodiode 4025 is bonded with gold wire It is electrically connected with the pin 403 on the TO tube socket 402 to realize the optical power monitoring function of the photodiode 4025.

The present disclosure embeds the lens originally arranged on the TO tube cap 401 on the TO4 tube socket 402. To ensure that the laser is hermetically sealed, a flat glass 404 can be provided at the light window of the TO tube cap 401. The flat glass 404 and TO The light window of the cap 401 is fixed by glass solder, so that the air-tight assembly of the TO cap 401 and the TO base 402 is realized. In addition, the flat glass 404 does not converge the signal beam, that is, the light beam emitted by the lens 4024 directly passes through the flat glass 404, and does not cause convergence or other effects on the light beam.

In other words, the signal beam emitted by the laser 4021 is reflected by the reflector 4023 and converted into a signal beam that is consistent with the transmission direction of the TO cap 401. The reflected signal beam is converted into convergent light through the lens 4024, and the convergent light directly passes through the flat glass. 404 is coupled to an external optical fiber.

There are currently two types of lasers for optical modules, one is DML (Directly Modulated Laser), and the other is EML (Electlro-absorption Modulated Laser). EML is the electro-absorption modulator EAM and The integrated device of DFB laser has better effect than DML, and the power consumption is also higher. Compared with DML, EML adds a refrigerator, metal base, thermistor (not marked in the figure), capacitor (not marked in the figure), etc.

FIG. 7 is a schematic structural diagram of another light emitting device provided by an embodiment of the disclosure, and FIG. 8 is an exploded schematic diagram of another light emitting device provided by an embodiment of the disclosure. As shown in FIG. 7 and FIG. 8, the light emitting device further includes a refrigerator 4027, which is generally pasted on the TO tube holder 402 with silver glue to dissipate heat from optoelectronic devices such as the laser 4021 and the photodiode 4025. That is, the laser 4021, photodiode 4025 and other optoelectronic devices are arranged on the refrigerator 4027, and the photodiode 4025 is used as an active heat sink. The heat generated by the laser 4021, photodiode 4025 and other optoelectronic devices is transferred to the TO tube holder 402 through the refrigerator 4027 for heat dissipation. .

In order to facilitate the installation of optoelectronic devices such as the laser 4021, photodiode 4025, etc., the refrigerator 4027 is provided with a metal base 4028, which is pasted on the refrigerator 4027 with silver glue, and the laser 4021, mirror 4023, photodiode 4025, etc. The optoelectronic device is pasted on the metal base 4028 with glue. In this example, the material of the metal base 4028 includes, but is not limited to, tungsten copper, raftable alloy, SPCC (Steel Plate Cold rolled Commercial, cold rolled carbon steel), copper, etc., to facilitate the transfer of heat generated by the optoelectronic device to the refrigerator 4027. Heat dissipation.

FIG. 9 is a partial structural diagram of another light emitting device provided by an embodiment of the disclosure, and FIG. 10 is a partial exploded diagram of another light emitting device provided by an embodiment of the disclosure. As shown in FIGS. 9 and 10, the laser 4021 is soldered on the laser ceramic heat sink 4022 with gold tin solder, and then the laser ceramic heat sink 4022 and the laser 4021 are horizontally pasted on the surface of the metal base 4028 with silver glue. The two opposite sides of the laser 4021 can emit light beams that are inconsistent with the light transmission direction of the TO cap 401, such as emitting a light beam whose main optical axis is parallel to the TO tube base 402, and a reflector 4023 is installed on the optical path of the front emitting light beam to reflect The reflective surface of the mirror 4023 corresponds to the laser 4021, and is used to reflect the beam emitted by the laser 4021 into a beam consistent with the light transmission direction of the TO cap 401, for example, the main optical axis of the reflected beam is perpendicular to the TO tube base 402.

The reflector 4023 is provided with a bottom platform, a top platform, and a slope connecting the bottom platform and the top platform. The bottom platform is fixed on the metal base 4028 with glue. The slope is used to reflect the signal beam from the laser 4021, so that the reflected signal beam direction It is consistent with the light transmission direction of the TO cap 401.

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

A photodiode 4025 is installed on the light path of the beam emitted from the back of the laser 4021. The photodiode 4025 is pasted on the PD ceramic heat sink 4026 with silver glue, and the PD ceramic heat sink 4026 is pasted on the metal base 4028 with glue for detecting the laser. The optical power of the beam emitted from the back of the 4021.

The laser 4021 and the photodiode 4025 fixed on the metal base 4028 are connected to the corresponding pin 403 on the TO tube base 402 by gold wire bonding to realize the independent electrical connection of the laser anode and the laser cathode to the outside, and realize the photodiode 4025 is electrically connected to the outside.

The laser 4021 pasted on the metal base 4028 and the signal beam of the TO cap 401 in the transmission direction are not consistent, the signal beam is reflected by the reflector 4023 and converted into a signal beam consistent with the transmission direction of the TO cap 401, and the reflected signal The light beam is condensed via the lens 4024.

FIG. 11 is a schematic diagram of an optical path of a laser beam emitted by an embodiment of the disclosure. As shown in Figure 11, the lens 4024 can be a point-to-point converging lens. The laser 4021 emits a signal beam that is inconsistent with the light transmission direction of the TO tube cap 401, such as a signal beam whose main optical axis is parallel to the TO tube socket 402, and the signal beam is reflected The mirror 4023 is reflected and converted into a signal beam whose main optical axis is perpendicular to the TO tube holder 402. The reflected signal beam is converted into a convergent light through a point-to-point converging lens. The purpose of laser coupling to optical fiber.

FIG. 12 is a schematic diagram of an optical path of another laser beam emitted by an embodiment of the disclosure. As shown in FIG. 12, the lens 4024 can also be a collimating lens, and then a corresponding converging lens 500 is arranged between the TO cap 401 and the external optical fiber 101. In this way, the laser 4021 emits a signal beam whose main optical axis is parallel to the TO tube holder 402. The signal beam is reflected by the reflector 4023 and converted into a signal beam whose main optical axis is perpendicular to the TO tube holder 402. The reflected signal beam is collimated. The lens is converted into a collimated beam, the collimated beam passes through the flat glass 404, and is converted into a condensed beam through the condensing lens 500 to be coupled to the external optical fiber 101, achieving the purpose of coupling the laser to the optical fiber.

In this example, the material of the lens 4024 mainly includes glass, silicon, and plastic PEI.

The reflector 4023 is used to receive the signal beam emitted by the laser 4021 that is inconsistent with the light transmission direction of the TO cap 401, and convert the signal light beam into a light beam that is consistent with the light transmission direction of the TO cap 401. FIG. 13 is a schematic diagram of a typical light path provided by an embodiment of the disclosure. As shown in Figure 13, the main optical axis of the laser 4021 can emit light perpendicular to the central axis of the TO tube holder 402, and the reflector 4023 can be a 45-degree reflecting prism. When the signal beam emitted by the laser 4021 is transmitted to the reflecting surface of the reflector 4023 , After 45 degree reflection, the horizontal beam is transformed into the reflected beam of the vertical TO tube holder 402.

FIG. 14 is a schematic diagram of another optical path provided by an embodiment of the disclosure. As shown in Figure 14, the main optical axis of the laser 4021 can also be at a preset angle with the central axis of the TO tube holder 402. The angle between the reflector 4023 and the central axis of the TO tube holder 402 is not 45 degrees, such as reflection The angle between the mirror 4023 and the central axis of the TO tube holder 402 is 44 degrees or 46 degrees, etc., as long as the light emitting direction of the laser 4021 is rotated by a matching angle according to the reflection principle during assembly, so that the main optical axis of the laser 4021 emits the beam After being reflected by the reflecting mirror 4023, it is perpendicular to the TO socket 402.

The angle between the reflector 4023 and the laser 4021 provided by the embodiment of the present disclosure is not limited to the angle of the above embodiment. As long as the angle between the reflective surface of the reflector 4023 and the laser emitting direction is a matching angle, the reflector 4023 can It suffices to reflect the light beam emitted by the laser 4021 into a light beam consistent with the light transmission direction of the TO cap 401, which all fall within the protection scope of the embodiments of the present disclosure.

The light emitting device in the optical module provided by the embodiment of the present disclosure adopts TO package, which includes a TO tube socket and a TO tube cap for packaging the TO tube socket. A laser, a mirror, a lens, and a photoelectric are placed on the surface of the TO tube socket. Photoelectric devices such as diodes. There are multiple pins on the TO tube base. The positive and negative electrodes of the laser are respectively electrically connected with the corresponding pins on the TO tube base by gold wire bonding to produce light transmission with the TO tube cap. Signal beams with inconsistent directions; the reflector is set on the light path of the signal beam on the front of the laser to reflect the signal beam from the laser to convert the signal beam that is inconsistent with the light transmission direction of the TO tube cap into light transmission with the TO tube cap The signal beam with the same direction; the lens is set above the reflector to converge the reflected signal beam, and according to the principle of reflection, the coaxiality of the lens and the reflection point of the reflector is ensured, and the optical height of the lens relative to the laser is realized. Accurate alignment improves the coupling efficiency; the photodiode is arranged on the optical path of the signal beam on the back of the laser, and it is electrically connected to the corresponding pin on the TO socket by means of gold wire bonding to detect the light emitted by the laser. Power, the laser can be dynamically adjusted according to the detected optical power of the laser to ensure the constant luminous power of the laser; flat window glass is installed at the optical window of the TO tube cap, and the TO tube cap and the TO tube base are capacitively welded to achieve The hermetically sealed package meets the reliability requirements of the laser.

The laser light path of the light emitting device in the optical module provided by the embodiment of the present disclosure may be: the laser emits a signal beam whose main optical axis is parallel to the TO tube base, and converts the signal beam to the main optical axis perpendicular to the TO tube base through a reflector. The signal beam and the reflected signal beam are converted into convergent light through the convergent lens. The convergent light passes through the flat window glass and is convergently coupled to the external optical fiber to realize the purpose of coupling the laser into the optical fiber.

In the optical module provided by the embodiments of the present disclosure, the lens is built into the TO tube holder. Compared with arranging the lens on the TO tube cap, the distance between the laser and the lens is reduced, the focal length of the lens is reduced, and the coupling efficiency is improved. In addition, the deviation of the optical path caused by the poor sealing and welding accuracy of the traditional TO tube cap is solved, the fluctuation of the optical fiber coupling efficiency is reduced, and the coupling efficiency is further improved.

It should be noted that in this specification, the terms "including", "including" or any other variations thereof are intended to cover non-exclusive inclusion, so that a circuit structure, article or device including a series of elements not only includes those elements, It also includes other elements that are not explicitly listed, or elements inherent to the circuit structure, article, or device. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the circuit structure, article or device that includes the element.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, not to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions recorded in the foregoing embodiments are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

An optical module, characterized in that it comprises:

Circuit board

The light emitting device is electrically connected to the circuit board through a pin, and is used to emit a light beam;

Wherein, the light emitting device includes:

TO socket with a plurality of said pins;

A TO tube cap, which is covered on the TO tube socket, and a transparent light window is provided on the TO tube cap for transmitting the light beam;

A laser, arranged on the surface of the TO tube socket, electrically connected to the pin, for emitting a signal beam, and the light emitting direction of the laser is inconsistent with the light transmitting direction of the TO tube cap;

A reflecting mirror is provided with a bottom platform, a top platform, and a slope connecting the bottom platform and the top platform, the bottom platform is fixed on the TO tube socket, and the slope is used to reflect the signal beam from the laser , So that the light emission direction of the signal beam after reflection is consistent with the light transmission direction of the TO cap;

The lens is arranged on the surface of the top platform of the reflector, and is used to converge the reflected signal beam, so that the converged beam is emitted from the light window of the TO tube cap;

The photodiode is arranged on the side of the laser facing away from the reflector, fixed laterally on the TO socket, and electrically connected to the pin, for detecting the optical power of the beam emitted by the laser.
The optical module according to claim 1, wherein the reflector is further provided with a side surface close to the emitting surface of the laser, the side surface is respectively connected to the bottom platform and the inclined surface, and the side surface is perpendicular to The bottom platform.
The optical module according to claim 1, wherein the reflector comprises a base and a flat glass coated with a reflective film, the base is arranged on the surface of the TO socket; the reflective film coated The flat glass is arranged on the inclined surface of the base, and is used to reflect the light beam emitted by the laser to the lens.
The optical module according to claim 1, wherein the relative distance between the lens and the laser is the focal length of the lens.
The optical module according to claim 4, wherein the lens is a convergent lens for convergently coupling the reflected signal beam to an external optical fiber.
4. The optical module according to claim 4, wherein the lens is a collimating lens for converting the reflected signal beam into a collimated beam.
The optical module according to claim 1, wherein the central axis of the laser and the central axis of the TO tube holder are at a predetermined angle, and the angle of the reflecting surface of the mirror is relative to the central axis of the laser. Matching, so that the light exit direction of the laser beam emitted by the laser is reflected by the reflector and is consistent with the light transmission direction of the TO cap.
The optical module according to claim 1, wherein a flat glass is provided at the light window, and the light beam emitted by the lens directly passes through the flat glass.
An optical module, characterized in that it comprises:

Circuit board

The light emitting device is electrically connected to the circuit board through a pin, and is used to emit a light beam;

Wherein, the light emitting device includes:

TO socket with a plurality of said pins;

A TO tube cap, which is covered on the TO tube socket, and a transparent light window is provided on the TO tube cap for transmitting the light beam;

A refrigerator, arranged on the surface of the TO tube socket, for adjusting the heat of the light emitting device;

The metal base is arranged on the surface of the refrigerator;

A laser, which is arranged on the surface of the metal base, is electrically connected to the pin, and is used to emit a signal beam, and the light-emitting direction of the laser is inconsistent with the light-transmitting direction of the TO cap;

The reflecting mirror is provided with a bottom platform, a top platform, and a slope connecting the bottom platform and the top platform, the bottom platform is fixed on the metal base, and the slope is used to reflect the signal beam from the laser, So that the light emitting direction of the signal beam after reflection is consistent with the light transmitting direction of the TO cap;

The lens is arranged on the surface of the top platform of the reflector, and is used to converge the reflected signal beam so that the converged beam is emitted from the light window of the TO tube cap;

The photodiode is arranged on the side of the laser facing away from the reflector, fixed laterally on the metal base, and electrically connected with the pin, for detecting the optical power of the beam emitted by the laser.
The optical module according to claim 9, wherein the reflector comprises a base and a plane glass coated with a reflective film, the base is arranged on the surface of the metal base; the plane coated with the reflective film Glass is arranged on the inclined surface of the base for reflecting the light beam emitted by the laser to the lens.