CN218549071U

CN218549071U - Electro-absorption modulation laser and optical module

Info

Publication number: CN218549071U
Application number: CN202222484594.0U
Authority: CN
Inventors: 王火雷; 章力明
Original assignee: Hisense Broadband Multimedia Technology Co Ltd
Current assignee: Hisense Broadband Multimedia Technology Co Ltd
Priority date: 2022-09-19
Filing date: 2022-09-19
Publication date: 2023-02-28
Anticipated expiration: 2032-09-19
Also published as: WO2024060439A1

Abstract

The embodiment of the application discloses electroabsorption modulated laser and optical module, electroabsorption modulated laser includes: the device comprises a substrate, and a DFB quantum well and an EAM quantum well which are arranged above the substrate side by side. And the N-face electrode is arranged below the substrate. And the grating layer is arranged above the DFB quantum well. And the conductive covering layer is arranged above the grating layer and the EAM quantum well. The high-reflection coating layer and the anti-reflection coating layer form a closed space together with the N-surface electrode and the conductive covering layer; a window area is arranged between the anti-reflection coating layer and the conductive covering layer; the window region includes: an InP filling area and an InGaAs light absorption area; the InP filling area is positioned between the substrate and the InGaAs light absorption area. The emergent light of the signal light in the InP window area is changed into space light for transmission from waveguide light, so that the end face reflection of a light-emitting face is reduced, and meanwhile, the InGaAs light-absorbing area can prevent the signal light from being emitted out through the InP window area to form side light spots, and the coupling efficiency of the light is improved.

Description

Electro-absorption modulation laser and optical module

Technical Field

The application relates to the technical field of communication, in particular to an electro-absorption modulation laser and an optical module.

Background

With the development of new services and application modes such as cloud computing, mobile internet, video and the like, the development and progress of the optical communication technology becomes more and more important. In the optical communication technology, an optical module is a tool for realizing the interconversion of optical signals and is one of key devices in optical communication equipment, and the transmission rate of the optical module is continuously increased along with the development requirement of the optical communication technology.

Among them, the electro-absorption modulated semiconductor laser is an important tool for converting an electric signal into an optical signal. In the optical path structure using optical fiber to transmit light beam, the semiconductor laser is used as light source, and the optical fiber and the optical receiver are connected by using coupling technique, so the performance of the optical fiber communication system is directly affected by the level of coupling efficiency.

SUMMERY OF THE UTILITY MODEL

The application provides an electro-absorption modulation laser and an optical module to improve optical coupling efficiency of the optical module.

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

the embodiment of the application discloses electroabsorption modulated laser and optical module, electroabsorption modulated laser includes: the device comprises a substrate, and a DFB quantum well and an EAM quantum well which are arranged above the substrate side by side;

the N-face electrode is arranged below the substrate;

a grating layer disposed over the DFB quantum well,

a conductive capping layer disposed over the grating layer and the EAM quantum well;

the high-reflection coating layer and the anti-reflection coating layer are oppositely arranged and form a closed space with the N-surface electrode and the conductive covering layer;

a window area is arranged between the anti-reflection coating layer and the conductive covering layer;

the window region includes: an InP filling area and an InGaAs light absorption area; the InP filling region is located between the substrate and the InGaAs light absorption region.

Has the beneficial effects that:

the embodiment of the application discloses electroabsorption modulated laser and optical module, electroabsorption modulated laser includes: the device comprises a substrate, and a DFB quantum well and an EAM quantum well which are arranged above the substrate side by side. And the N-face electrode is arranged below the substrate. And the grating layer is arranged above the DFB quantum well. And the conductive covering layer is arranged above the grating layer and the EAM quantum well. The high-reflection coating layer and the anti-reflection coating layer are oppositely arranged and form a closed space with the N-surface electrode and the conductive covering layer; a window area is arranged between the anti-reflection coating layer and the conductive covering layer; the window region includes: an InP filling area and an InGaAs light absorption area; the InP filling area is positioned between the substrate and the InGaAs light absorption area. After signal light is modulated through the EAM quantum well, emergent light in an InP window area is changed into space light for transmission from waveguide light, so that end face reflection of a light-emitting face is reduced, meanwhile, the InGaAs light absorption area is a strong absorption layer, the situation that the signal light is emitted from the side face of a laser chip through the space of the InP window area to form side light spots can be avoided, and the coupling efficiency of light is improved.

Drawings

In order to more clearly illustrate the technical solutions of the present disclosure, the drawings required to be used in some embodiments of the present disclosure will be briefly described below, and it is apparent that the drawings in the following description are only drawings of some embodiments of the present disclosure, and other drawings can be obtained by those skilled in the art according to these drawings. Furthermore, the drawings in the following description may be considered as schematic diagrams, and do not limit the actual size of products, the actual flow of methods, the actual timing of signals, and the like, involved in the embodiments of the present disclosure.

FIG. 1 is a connection diagram of an optical communication system according to some embodiments;

FIG. 2 is a block diagram of an optical network terminal according to some embodiments;

FIG. 3 is a block diagram of a light module according to some embodiments;

FIG. 4 is an exploded view of a light module according to some embodiments;

fig. 5 is an exploded view of a light emitting device according to an embodiment of the present disclosure;

fig. 6 is a schematic view of another exploded structure of a light emitting device provided in an embodiment of the present application;

fig. 7 is a schematic partial structure diagram of a light emitting device according to an embodiment of the present application;

fig. 8 is a first schematic diagram of an electro-absorption modulated semiconductor laser structure according to an example of the present application;

fig. 9 is a diagram of an electroabsorption modulated semiconductor laser structure according to an example of the present application;

fig. 10 is a schematic cross-sectional view of an electro-absorption modulated semiconductor laser according to an example of the present application.

Detailed Description

The technical solutions in some embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present disclosure, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments provided in the present disclosure are within the scope of protection of the present disclosure.

In an optical communication system, an optical signal is used to carry information to be transmitted, and the optical signal carrying the information is transmitted to information processing equipment such as a computer through information transmission equipment such as an optical fiber or an optical waveguide, so as to complete information transmission. Since light has a passive transmission characteristic when transmitted through an optical fiber or an optical waveguide, low-cost, low-loss information transmission can be realized. Since a signal transmitted by an information transmission device such as an optical fiber or an optical waveguide is an optical signal and a signal that can be recognized and processed by an information processing device such as a computer is an electrical signal, it is necessary to perform interconversion between the electrical signal and the optical signal 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.

The optical module realizes the function of interconversion between the optical signal and the electrical signal in the technical field of optical communication. The optical module comprises an optical port and an electric port, the optical module realizes optical communication with information transmission equipment such as optical fibers or optical waveguides and the like through the optical port, realizes electric connection with an optical network terminal (such as an optical modem) through the electric port, and the electric connection is mainly used for power supply, I2C signal transmission, data information transmission, grounding and the like; the optical network terminal transmits the electric signal to the computer and other information processing equipment through a network cable or a wireless fidelity (Wi-Fi).

Fig. 1 is a connection diagram of an optical communication system. As shown in fig. 1, the optical communication system includes a remote server 1000, a local information processing device 2000, an optical network terminal 100, an optical module 200, an optical fiber 101, and a network cable 103.

One end of the optical fiber 101 is connected to the remote server 1000, and the other end is connected to the optical network terminal 100 through the optical module 200. The optical fiber itself can support long-distance signal transmission, for example, signal transmission of thousands of meters (6 km to 8 km), on the basis of which if a repeater is used, theoretically infinite distance transmission can be realized. Therefore, in a typical optical communication system, the distance between the remote server 1000 and the optical network terminal 100 may be several kilometers, tens of kilometers, or hundreds of kilometers.

One end of the network cable 103 is connected to the local information processing device 2000, and the other end is connected to the optical network terminal 100. The local information processing apparatus 2000 may be any one or several of the following apparatuses: router, switch, computer, cell-phone, panel computer, TV set etc..

The physical distance between the remote server 1000 and the optical network terminal 100 is greater than the physical distance between the local information processing apparatus 2000 and the optical network terminal 100. The connection between the local information processing apparatus 2000 and the remote server 1000 is made by the optical fiber 101 and the network cable 103; and the connection between the optical fiber 101 and the network cable 103 is completed by the optical module 200 and the optical network terminal 100.

The optical module 200 includes an optical port configured to access the optical fiber 101 and an electrical port, so that the optical module 200 establishes a bidirectional optical signal connection with the optical fiber 101; the electrical port is configured to be accessed into the optical network terminal 100, so that the optical module 200 establishes a bidirectional electrical signal connection with the optical network terminal 100. The optical module 200 converts an optical signal and an electrical signal to each other, so that an information connection is established between the optical fiber 101 and the optical network terminal 100. For example, an optical signal from the optical fiber 101 is converted into an electrical signal by the optical module 200 and then input to the optical network terminal 100, and an electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module 200 and input to the optical fiber 101. Since the optical module 200 is a tool for implementing the interconversion between the optical signal and the electrical signal, and has no function of processing data, information is not changed in the above-mentioned photoelectric conversion process.

The optical network terminal 100 includes a housing (housing) having a substantially rectangular parallelepiped shape, and an optical module interface 102 and a network cable interface 104 provided on the housing. The optical module interface 102 is configured to access the optical module 200, so that the ont 100 establishes a bidirectional electrical signal connection with the optical module 200; the network cable interface 104 is configured to access the network cable 103 such that the optical network terminal 100 establishes a bi-directional electrical signal connection with the network cable 103. The optical module 200 is connected to the network cable 103 via the optical network terminal 100. For example, the onu 100 transmits the electrical signal from the optical module 200 to the network cable 103, and transmits the electrical signal from the network cable 103 to the optical module 200, so that the onu 100 can monitor the operation of the optical module 200 as an upper computer of the optical module 200. The upper computer of the Optical module 200 may include an Optical Line Terminal (OLT) and the like in addition to the Optical network Terminal 100.

The remote server 1000 establishes a bidirectional signal transmission channel with the local information processing device 2000 through the optical fiber 101, the optical module 200, the optical network terminal 100, and the network cable 103.

Fig. 2 is a configuration diagram of the optical network terminal, and fig. 2 only shows a configuration of the optical module 200 of the optical network terminal 100 in order to clearly show a connection relationship between the optical module 200 and the optical network terminal 100. As shown in fig. 2, the optical network terminal 100 further includes a circuit board 105 disposed within the housing, a cage 106 disposed on a surface of the circuit board 105, a heat sink 107 disposed on the cage 106, and an electrical connector disposed inside the cage 106. The electrical connector is configured to access an electrical port of the optical module 200; the heat sink 107 has a projection such as a fin that increases a heat radiation area.

The optical module 200 is inserted into a cage 106 of the optical network terminal 100, the cage 106 holds the optical module 200, and heat generated by the optical module 200 is conducted to the cage 106 and then diffused by a heat sink 107. After the optical module 200 is inserted into the cage 106, an electrical port of the optical module 200 is connected to an electrical connector inside the cage 106, so that the optical module 200 is connected to the optical network terminal 100 by a bidirectional electrical signal. Further, an optical port of the optical module 200 is connected to the optical fiber 101, and the optical module 200 establishes bidirectional optical signal connection with the optical fiber 101.

FIG. 3 is a block diagram of a light module according to some embodiments. As shown in fig. 3, the optical module 200 includes a housing (shell), a circuit board 300 disposed in the housing, and an optical transceiver module 400.

The shell comprises an upper shell 201 and a lower shell 202, wherein the upper shell 201 is covered on the lower shell 202 to form the shell with two openings; the outer contour of the housing generally appears square.

In some embodiments of the present disclosure, the lower housing 202 includes a bottom plate 2021 and two lower side plates 2022 located at both sides of the bottom plate 2021 and disposed perpendicular to the bottom plate 2021; the upper case 201 includes a cover 2011, and the cover 2011 covers the two lower side plates 2022 of the lower case 202 to form the above case.

In some embodiments, the lower housing 202 includes a bottom plate 2021 and two lower side plates 2022 located at both sides of the bottom plate 2021 and disposed perpendicular to the bottom plate 2021; the upper housing 201 includes a cover 2011 and two upper side plates located on two sides of the cover 2011 and perpendicular to the cover 2011, and the two upper side plates are combined with the two lower side plates 2022 to cover the upper housing 201 on the lower housing 202.

The direction of the connecting line of the two

openings

204 and 205 may be the same as the length direction of the optical module 200, or may not be the same as the length direction of the optical module 200. For example, the opening 204 is located at an end portion (right end in fig. 3) of the optical module 200, and the opening 205 is also located at an end portion (left end in fig. 3) of the optical module 200. Alternatively, the opening 204 is located at an end of the optical module 200, and the opening 205 is located at a side of the optical module 200. The opening 204 is an electrical port, and a gold finger of the circuit board 300 extends out of the electrical port 204 and is inserted into an upper computer (for example, the optical network terminal 100); the opening 205 is an optical port configured to receive the external optical fiber 101, so that the external optical fiber 101 is connected to the optical transceiver module 400 inside the optical module 200.

The upper shell 201 and the lower shell 202 are combined to facilitate the installation of the components such as the circuit board 300 and the optical transceiver module 400 into the shells, and the upper shell 201 and the lower shell 202 form encapsulation protection for the components. In addition, when the devices such as the circuit board 300 and the optical transceiver module 400 are assembled, the positioning components, the heat dissipation components and the electromagnetic shielding components of the devices are convenient to arrange, and the automatic production is facilitated.

In some embodiments, the upper housing 201 and the lower housing 202 are generally made of metal materials, which is beneficial to achieve electromagnetic shielding and heat dissipation.

In some embodiments, the optical module 200 further includes an unlocking component located outside its housing, and the unlocking component is configured to implement a fixed connection between the optical module 200 and an upper computer, or to release the fixed connection between the optical module 200 and the upper computer.

Illustratively, the unlocking member is located on the outer wall of the two lower side plates 2022 of the lower housing 202, and has a snap-fit member that matches with a cage of the upper computer (e.g., the cage 106 of the optical network terminal 100). When the optical module 200 is inserted into the cage of the upper computer, the optical module 200 is fixed in the cage of the upper computer by the engaging member of the unlocking member; when the unlocking member is pulled, the engaging member of the unlocking member moves along with the unlocking member, and further the connection relationship between the engaging member and the upper computer is changed, so that the engagement relationship between the optical module 200 and the upper computer is released, and the optical module 200 can be drawn out from the cage of the upper computer.

The circuit board 300 includes circuit traces, electronic components, and chips, and the electronic components and the chips are connected together by the circuit traces according to a circuit design to implement functions of power supply, electrical signal transmission, grounding, and the like. Examples of the electronic components include capacitors, resistors, transistors, and Metal-Oxide-Semiconductor Field-Effect transistors (MOSFETs). The chip includes, for example, a Micro Controller Unit (MCU), a laser driving chip, a limiting amplifier (limiting amplifier), a Clock and Data Recovery (CDR) chip, a power management chip, and a Digital Signal Processing (DSP) chip.

The circuit board 300 is generally a rigid circuit board, which can also perform a bearing function due to its relatively rigid material, for example, the rigid circuit board can stably bear the electronic components and chips; when the optical transceiver component is positioned on the circuit board, the rigid circuit board can also provide smooth bearing; the rigid circuit board can also be inserted into an electric connector in the upper computer cage.

The circuit board 300 further includes a gold finger formed on an end surface thereof, the gold finger being composed of a plurality of pins independent of each other. The circuit board 300 is inserted into the cage 106 and electrically connected to the electrical connector in the cage 106 by gold fingers. The gold fingers may be disposed on only one side of the circuit board 300 (e.g., the upper surface shown in fig. 4), or may be disposed on both upper and lower sides of the circuit board 300, so as to adapt to the situation where the requirement of the number of pins is large. The golden finger is configured to establish an electrical connection with the upper computer to realize power supply, grounding, I2C signal transmission, data signal transmission and the like.

Of course, a flexible circuit board is also used in some optical modules. Flexible circuit boards are commonly used in conjunction with rigid circuit boards to supplement the rigid circuit boards. For example, a flexible circuit board may be used to connect the rigid circuit board and the optical transceiver module.

The optical transceiver component 400 includes a light emitting device configured to enable emission of an optical signal and a light receiving device configured to enable reception of the optical signal. Illustratively, the light emitting device and the light receiving device are combined together to form an integrated light transceiving component.

Fig. 5 is an exploded schematic view of a light emitting device according to an embodiment of the present disclosure; fig. 6 is a schematic diagram of another exploded structure of a light emitting device provided in an embodiment of the present application; the overall structure of the light emitting portion of the optical module of the present application is described below with reference to fig. 5 and 6. As shown in fig. 5 and 6, the light emitting device 400 includes an emission cover 401 and a housing 402, the emission cover 401 and the housing 402 are coupled to each other, and specifically, the emission cover 401 covers the housing 402 from above, one side wall of the housing 402 has an opening 404 for insertion of the circuit board 300, and the other side wall of the housing 402 has a through hole for insertion of the fiber optic adapter 403.

Specifically, the circuit board 300 extends into the housing 402 through the opening 404, and the circuit board 300 is fixed to the lower case 202; the circuit board 300 is plated with metal traces, and the optical device can be electrically connected to the corresponding metal traces by wire bonding, so as to electrically connect the optical device inside the housing 402 and the circuit board 300.

The signal light emitted by the light emitting device is emitted into the through hole, the optical fiber adapter 403 extends into the through hole 405 to be coupled and receive the signal light, the assembling structure design can enable the optical fiber adapter 403 to move back and forth in the through hole 405, the required size of the optical fiber between the light emitting device and the optical fiber plug can be adjusted, and when the optical fiber is short, the optical fiber adapter can move back (towards the outer direction of the cavity) in the through hole to meet the requirement of the connecting size; when the optical fiber is longer, the optical fiber adapter can be moved forwards (towards the inner direction of the cavity) in the through hole so as to straighten the optical fiber and avoid bending the optical fiber. The fiber adapter 403 is inserted into the through hole to achieve fixation with the light emitting device 400; during assembly, the fiber optic adapters 403 may be moved within the through-holes to select a fixed position.

One side wall of the housing 402 has an opening 404 for insertion of the circuit board 300 and the other side wall of the housing 402 has a through hole for insertion of the fiber optic adapter 403.

In this embodiment, the optical device disposed in the housing 402 may optionally be further connected to the circuit board 300 through a pin, where the pin is designed to have a shape adapted to the lower housing, one end of the pin is inserted into the lower housing, and a metal trace is plated on the end of the pin, the optical device may be electrically connected to the corresponding metal trace through a wire bonding manner, one end of the pin disposed in the housing 402 is provided with a plurality of pins electrically connected to the metal trace, and the pins are inserted into the circuit board 300 and soldered together to further electrically connect the optical device in the housing 402 to the circuit board 300, and of course, the pins on the pin may also be directly soldered to the circuit board 300 to electrically connect the optical device in the housing 402 to the circuit board 300.

In the signal transmission process, the optical transmission sub-device in the housing 402 receives the electrical signal transmitted by the circuit board 300, converts the electrical signal into an optical signal, and then transmits the optical signal to the outside of the optical module after entering the optical fiber adapter 403.

The light emitting device has a package structure TO package laser chips and the like, and the existing package structure comprises a coaxial package TO-CAN, a silicon optical package, a chip-on-board LENS assembly package COB-LENS and a micro-optical XMD package. The package is further divided into hermetic package and non-hermetic package, which provides a stable and reliable working environment for the laser chip on one hand and forms external electrical connection and optical output on the other hand. The light emitting device may be provided with one or more sets of COC structures.

Fig. 7 is a schematic partial structure diagram of a light emitting device according to an embodiment of the present disclosure; as shown in fig. 7, the COC structure in the embodiment of the present application includes: the substrate 501 is disposed in the housing 402 and is made of alumina ceramic, aluminum nitride ceramic, or the like. The ceramic substrate 501 is engraved with functional circuitry of the laser chip for signal transmission, such as transmission line 502. The surface of the ceramic substrate 501 is provided with an electric absorption modulation semiconductor laser 503, the electric absorption modulation semiconductor laser is an integrated device of a laser DFB and an electric absorption modulator EA, the laser DFB converts an electric signal into an optical signal, and the electric absorption modulator EA outputs the optical signal after coding modulation, so that the output optical signal carries information. The EML laser 503 is provided with a light emitting pad, an electro-absorption modulation pad, and a negative electrode pad, the negative electrode pad is disposed on the lower surface of the EML laser, and the light emitting pad and the electro-absorption modulation pad are disposed on the upper surface of the electro-absorption modulation semiconductor laser 503.

Fig. 8 is a schematic diagram of a first electro-absorption modulated semiconductor laser structure of an example of the present application, and fig. 9 is a schematic diagram of a second electro-absorption modulated semiconductor laser structure of an example of the present application; fig. 10 is a schematic cross-sectional view of an electro-absorption modulated semiconductor laser according to an example of the present application. Fig. 8 and 9 show the electroabsorption modulated semiconductor laser structure from different angles. As shown in fig. 8, 9 and 10, the structure of the electro-absorption modulated semiconductor laser according to the example of the present application is mainly composed of two parts: respectively DFB-LD region 510 and EAM absorption modulation region 520. When the chip is in operation, the DFB light source electrode 511 is energized with a dc current to emit laser light of a specific wavelength, which then enters the EAM quantum well 522. The EAM quantum well 522 modulates the laser light source based on the QCSE effect at different voltages of the EAM absorbing electrode 510 to produce a high frequency modulated optical signal.

An electro-absorption modulated semiconductor laser comprising: an N-face electrode 570, a high reflection coating 540, an anti-reflection coating 550, an InP substrate 580, a DFB quantum well 513, an EAM quantum well 522, a grating layer 512, a DFB light source electrode 511, an EAM absorption electrode 521, a first isolation region 530, a conductive covering 590 and a window region 560.

The N-face electrode 570, the high-reflection coating layer 540, the anti-reflection coating layer 550 and the conductive covering layer 6 form a closed space; the high-reflection coating layer 540 and the anti-reflection coating layer 550 are oppositely arranged; the N-face electrode 570 and the conductive covering layer 590 are arranged between the high-reflection coating layer 540 and the antireflection coating layer 550 and at two ends far away from each other; the DFB quantum well 513 and EAM quantum well 522 are on an InP substrate 580; a grating layer 512 is arranged on the DFB quantum well 513, and the grating covering layer covers the grating layer 512; a conductive cover 590 overlies the grating cover; the DFB light source electrode 511 and the EAM absorption electrode 521 are disposed on the upper surface of the conductive capping layer 590. Window region 560 is located inside antireflective coating 550 and is located between antireflective coating 550 and EAM quantum well 522. The window region 560 includes: inP filled region 561 and InGaAs light absorbing region 562, where: the InGaAs light absorption region 562 is disposed above the InP filled region 561. After signal light is modulated by the EAM quantum well 522, emergent light in an InP window area is changed into space light for transmission from waveguide light, so that end face reflection of a light emergent face is reduced, meanwhile, an InGaAs light absorption area is a strong absorption layer, the situation that the signal light is emitted from the side face of a laser chip through the space of the InP window area to form side light spots can be avoided, and the coupling efficiency of the light is improved. In the application, the window area 560 comprises InP and InGaAs materials, so that reflection of the light-emitting end face can be reduced, interference of end face reflection on laser signals is reduced, and stable high-frequency output signals are obtained; meanwhile, the quality of the light beam of the output light can be effectively improved, and the coupling efficiency of the rear-end electro-absorption modulation semiconductor laser is further improved.

In the application, the tail end of the DFB quantum well 513 is connected with the head end of the EAM quantum well 521, the tail end of the EAM quantum well 521 is connected with the head end of the window area, the upper end of the DFB quantum well 513 is provided with a grating layer 512, and the ratio of the length of the grating layer 512 to the total length of the DFB-LD area 510 is 0.3-1. The right end of the grating layer 512 is aligned with the right end of the DFB-LD region, a conductive covering layer 590 is deposited above the grating layer, a first isolation region 530 is etched on the conductive covering layer 590, DFB light source electrodes 511 and EAM absorption electrodes 521 are respectively plated on the conductive covering layers 590 on the left side and the right side of the first electrical isolation region, meanwhile, an N-metal plated electrode layer is used as an N-surface electrode of the laser, a high-reflection film coating layer 540 is arranged on the left side end face of the electro-absorption modulation semiconductor laser, and an anti-reflection film coating 550 is arranged on the right side end face of a window of the electro-absorption modulation semiconductor laser.

In the present application, the DFB light source electrode 511 is a light emitting pad, the EAM absorbing electrode 521 is an electro-absorption modulation pad, and the N-plane electrode 570 is a negative pad.

The left end face of the electro-absorption modulation semiconductor laser is provided with a high-reflection coating layer 540 which can reflect light back to the light-emitting direction so as to increase the light power.

The anti-reflection coating layer 550 is arranged on the right end face of the window of the electro-absorption modulation semiconductor laser, so that the transmission of signal light is increased, and the light power is increased.

In some examples of the present application, the central axis of the DFB quantum well 513 is collinear with the central axis of the EAM quantum well 522, facilitating the transmission of light between the DFB quantum well and the EAM quantum well 522.

In some examples of the present application, antireflective coating 550 comprises: the device comprises a first SiO2 layer and a second TiO2 layer, wherein the first SiO2 layer and the first TiO2 layer are sequentially arranged along the direction departing from the electric absorption modulation semiconductor laser.

The high-reflection coating layer 540 comprises a third SiO2 layer, a second TiO2 layer, a third SiO2 layer, a third TiO2 layer, a fourth SiO2 layer and a fourth TiO2 layer which are sequentially arranged along the direction of the electro-absorption modulation semiconductor laser. The highly reflective coating 540 reflects light back to the light exit direction to increase the light power.

The width of the first isolation region 530 is 20um to 120um, and the first isolation region 530 is formed by etching a contact layer or by ion implantation. The width direction of the first isolation region 530 is the left-right direction shown in fig. 9.

In some examples of the present application, the thickness of the InGaAs light absorption region is 10nm to 1um, and the InGaAs light absorption region is made of InGaAs material, and has strong light absorption characteristics, so that light emission from the upper surface of the electroabsorption modulation semiconductor laser can be avoided.

In some examples of the present application, the N-side electrode 570 is located on the lower surface of the InP substrate 580, and the N-side electrode 570 may be formed by etching an electrode recess on the lower surface of the InP substrate 580 by wet or dry etching, and then plating an N-side metal layer on the electrode recess.

In some examples of the present application, the width of the window region 560 is 1um to 100um, and the window region is formed by means of MOCVD material epitaxy.

In some examples of the present application, the ratio of the length of grating layer 512 to the overall length of the quantum well is 0.3 to 1; the right end of grating layer 512 is aligned with the right end of the quantum well.

The projection of the window region on the high reflection coating layer covers the conductive covering layer, the DFB quantum well 513, the EAM quantum well 522 and the grating layer 512. The lower surface of the window area is connected with the InP substrate 580, the right end is connected with the anti-reflection coating layer, and the left end is connected with the EAM quantum well and the conductive covering layer at one time. The structure of the electro-absorption modulation semiconductor laser is mainly composed of two parts: a DFB-LD region 510 and an EAM absorption modulation region 520, respectively. When the chip is in operation, the DFB light source electrode 511 is energized with a dc current to emit laser light of a specific wavelength, which then enters the EAM quantum well 522. The EAM quantum well 522 modulates the laser light source based on the QCSE effect at different voltages of the EAM absorber electrode 510 to produce a high frequency modulated light signal.

The N-face electrode 570, the high-reflection coating layer 540, the anti-reflection coating layer 550 and the conductive covering layer 6 form a closed space; the high-reflection coating layer 540 and the anti-reflection coating layer 550 are oppositely arranged; the N-face electrode 570 and the conductive covering layer 590 are arranged between the high-reflection coating layer 540 and the antireflection coating layer 550 and at two ends far away from each other; the DFB quantum well 513 and EAM quantum well 522 are located on an InP substrate 580; a grating layer 512 is arranged on the DFB quantum well 513, and the grating covering layer covers the grating layer 512; a conductive cover 590 overlies the grating cover; the DFB light source electrode 511 and the EAM absorption electrode 521 are disposed on the upper surface of the conductive capping layer 590. The window region 560 is located inside the anti-reflection coating 550 and is disposed between the anti-reflection coating 550 and the EAM quantum well 522. The window region 560 includes: inP filled region 561 and InGaAs light absorbing region 562, where: the InGaAs light absorption region 562 is disposed above the InP filled region 561. After signal light is modulated by the EAM quantum well 522, emergent light in an InP window area is changed into space light for transmission from waveguide light, so that end face reflection of a light emergent face is reduced, meanwhile, an InGaAs light absorption area is a strong absorption layer, the situation that the signal light is emitted from the side face of a laser chip through the space of the InP window area to form side light spots can be avoided, and the coupling efficiency of the light is improved. In the application, the window area 560 comprises InP and InGaAs materials, so that reflection of the light-emitting end face can be reduced, interference of end face reflection on laser signals is reduced, and stable high-frequency output signals are obtained; meanwhile, the quality of the light beam of the output light can be effectively improved, and the coupling efficiency of the rear-end electro-absorption modulation semiconductor laser is further improved.

Since the above embodiments are all described by referring to and combining with other embodiments, the same portions are provided between different embodiments, and the same and similar portions between the various embodiments in this specification may be referred to each other. And will not be described in detail herein.

It is noted that, in this specification, relational terms such as "first" and "second," and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, 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 phrases "comprising a" \8230; "defining an element do not exclude the presence of additional 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 present disclosure. 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. An electroabsorption modulated laser, comprising: the device comprises a substrate, and a DFB quantum well and an EAM quantum well which are arranged above the substrate side by side;

the N-face electrode is arranged below the substrate;

a grating layer disposed over the DFB quantum well,

2. The electroabsorption modulated laser of claim 1, wherein the window region has a width of 1um to 100um; the thickness of the InGaAs light absorption area is 1 um-100 um; the InGaAs light absorption area is made of InGaAs materials.

3. The electroabsorption modulated laser of claim 1, wherein a central axis of the DFB quantum well is collinear with a central axis of the EAM quantum well.

4. The electroabsorption modulated laser of claim 1 wherein the ends of the DFB quantum wells meet at the head end of the EAM quantum wells, the ends of the EAM quantum wells meet at the head end of the window region, and the grating layer is disposed over the DFB quantum wells; the ratio of the length of the grating layer to the total length of the quantum well is 0.3-1; the right end of the grating layer is aligned with the right end of the quantum well.

5. The electroabsorption modulated laser of claim 1, wherein a DFB light source electrode, an EAM absorption electrode, and a first isolation region are disposed over the conductive cap layer;

the first isolation region is arranged between the DFB light source electrode and the EAM absorption electrode; the width of the first isolation region is 20 um-120 um.

6. The electroabsorption modulated laser of claim 1 wherein the highly reflective coating comprises, in order from the antireflective coating to the highly reflective coating: a third SiO2 layer, a second TiO2 layer, a third SiO2 layer, a third TiO2 layer, a fourth SiO2 layer and a fourth TiO2 layer;

along the anti-reflection coating layer to high reflection coating layer direction, anti-reflection coating layer includes: a first TiO2 layer and a first SiO2 layer.

7. A light module, comprising: an electroabsorption modulated laser as claimed in any one of claims 1 to 6.