WO2019128341A1

WO2019128341A1 - Laser chip, light-emitting component, light module and network device

Info

Publication number: WO2019128341A1
Application number: PCT/CN2018/107107
Authority: WO
Inventors: 程远兵; 余长亮; 李书; 杨素林; 李胜平; 程宁
Original assignee: 华为技术有限公司
Priority date: 2017-12-29
Filing date: 2018-09-21
Publication date: 2019-07-04
Also published as: CN109994926A

Abstract

A laser chip, a light-emitting component, a light module and a network device. The laser chip comprises: a laser (10) and a monitoring photodiode (20), wherein the laser and the monitoring photodiode are a monolithically integrated integration structure, and the laser and an active layer (30) of the monitoring photodiode are arranged on the same layer; and the laser is electrically isolated from the monitoring photodiode. The laser comprises a gain region (12) and at least one grating reflection region (13), wherein the gain region is electrically isolated from each grating reflection region, and the at least one grating reflection region transmits part of the laser emitted from the gain region to the monitoring photodiode; or the laser and the monitoring photodiode are provided with a second groove (36) therebetween and are electrically isolated by the second groove, and part of the laser emitted from the laser is projected to the monitoring photodiode. By means of monolithically integrating a laser and a monitoring photodiode, the cost of the whole laser chip is reduced, and the output efficiency of the laser chip is improved.

Description

Laser chip, light emitting component, optical module and network device

This application claims the priority of the Chinese Patent Application entitled "A Laser Chip, Light Emitting Module, Optical Module and Network Equipment" submitted by the Chinese Patent Office on December 29, 2017, with the application number of 201711486328.9. This is incorporated herein by reference.

Technical field

The present application relates to the field of communications technologies, and in particular, to a laser chip, a light emitting component, an optical module, and a network device.

Background technique

With the rapid spread of Internet video applications, high-bandwidth services such as 4K/8K HD, home cloud and video calling, and the increasing demand for bandwidth, PON (Passive Optical Network) has gradually replaced copper broadband. Access becomes the mainstream technology for fixed access networks. The PON system usually includes an OLT (Optical Line Terminate) at the central office (CO), an ODN (Optical Distribution Network) for branching/coupling or multiplexing/demultiplexing, and several ONUs (Optical). Network Unit, optical network unit). The so-called passive optical network means that the ODN between the OLT and the ONU does not have any active electronic equipment. Generally, the downlink adopts a time division multiplexing broadcast method, and the uplink adopts a time division multiple access method, and can flexibly form a topology structure such as a tree type, a star type, and a bus type. The typical structure is a tree structure. Each ONU/ONT can share the optical fiber between the OLT and the optical splitter, which saves the amount of fiber laying and has good business transparency. In principle, it can be used for signals of any standard and rate, and is easy to network. Expansion and maintenance. As a key component in the optical network, the optical modules in the OLT and ONU equipment are responsible for the photoelectric conversion and transmission of the network signals, which is the basis for the normal communication of the entire network. The important component in the optical module is the Transmitter Optical Subassembly (TOSA). The function of the TOSA is to convert the electrical signal into an optical signal and input it into the optical network for transmission. TOSA is generally packaged in a coaxial TO-CAN form. A typical TO-CAN is a combination of a metal base with a pin and a cap with a lens. Signal source for optical communication (laser chip, DML or EML) And the monitoring detectors are placed on the metal base in a certain form. The main optical devices in commercial TOSA currently include discrete laser chips (LD) and discrete monitor photodetectors (MPD). The use of discrete device chip packages requires multiple placement processes, and the optical coupling of LD and MPD requires an alignment process, adding a certain manufacturing cost. The monolithic integrated device of LD and MPD (Monitor Photodiode) can overcome the problems in the above discrete devices, significantly reduce the packaging cost of the device and improve the stability of the device. One of the most intuitive ways to integrate LD and monitor photodiodes is to use a monitor photodiode integrated at one end of the LD through monolithic integration technology, and light is output through the other end. In order to reduce the influence of the end phase on the single-mode yield of the device, the integrated device is usually coated with an anti-reflection film at both ends. However, since both ends of the integrated device are plated and etched, the output optical power is small, which is difficult to meet the PON high optical power budget. Since the monitoring photodiode is directly integrated at one end of the LD, the optical power entering the LD is large. In order to ensure that the monitoring photodiode operates in the linear region, a monitoring photodiode having a long cavity length is required, which increases the cost of the integrated device.

Summary of the invention

The present application provides a laser chip, a light emitting component, an optical module, and a network device for realizing high power operation of the laser chip and reducing the cost of the laser chip.

In a first aspect, a laser chip is provided, the laser chip includes: a laser and a monitor photodiode, and the laser and the monitor photodiode are monolithically integrated integrated structures, the laser and the monitor photodiode The active layer is disposed in the same layer; the laser is electrically isolated from the monitoring photodiode; wherein

The laser includes a gain region and at least one grating reflection region, the gain region being electrically isolated from each of the grating reflection regions, at least one of the grating reflection regions transmitting a portion of the laser light emitted by the gain region to the monitoring Photodiode; and the grating reflection area can also reflect the remaining laser light, thereby increasing the output power of the laser and improving the single mode yield.

Alternatively, a second trench is disposed between the laser and the monitor photodiode, and is electrically isolated by the second trench, and a portion of the laser light emitted by the laser is transmitted to the monitor photodiode.

In the above technical solution, the cost of the entire laser chip is reduced, and the output power of the laser chip is improved, so that the laser chip can be applied to high-power operation.

In a specific embodiment, the laser includes a first grating reflection region, a gain region, and a second grating reflection region which are sequentially electrically isolated, and the monitor photodiode is located away from the gain of the second grating reflection region. One side of the area.

In a specific embodiment, the active layer is provided with a plurality of first trenches disposed at intervals, the first grating reflective region, the gain region, the second grating reflective region, and the monitor photodiode Interposed by the first trench. Electrical isolation between the first grating reflection region, the gain region, the second grating reflection region, and the monitor photodiode is achieved by the trench. In a particular arrangement, the first trench has a width of 10 to 30 microns and a depth of 0.1 to 1 micron.

In a specific embodiment, the first trench is filled with protons or inert ions. The isolation effect during electrical isolation is further improved by injecting inert ions into the first trench, and the isolation resistance is greater than 10 kilo ohms.

In a specific embodiment, the inert ion is a proton or a cesium ion, which further enhances the electrical isolation effect.

In a specific embodiment, the length of the monitor photodiode is greater than 5 microns and less than 50 microns.

In a specific embodiment, the second grating reflective region has a length greater than 100 microns.

In a specific embodiment, the length of the first grating reflective region is less than 100 microns.

In a specific embodiment, the reflectivity of the first grating reflection zone should be less than 30% and the reflectance of the second grating reflection zone greater than 80%.

In a specific embodiment, the grating of the first grating reflection region and the second grating reflection region is a uniform grating, which can be fabricated by a holographic exposure method suitable for mass production.

In a specific embodiment, the grating period of the first grating reflection region and the second grating reflection region are the same, and the grating period is between 195 nm and 215 nm or between 235 nm and 250 nm.

In a specific embodiment, the gain region has a grating, and a grating period of the gain region is the same as a grating period of the first grating reflection region and the second grating reflection region.

In a specific embodiment, the laser includes: a gain region and a second grating reflection region;

The monitoring photodiode is located at a side of the second grating reflection region away from the gain region;

The laser chip further includes an electroabsorption modulator;

The electroabsorption modulator is located on a side of the gain region remote from the monitor photodiode and is electrically isolated from the gain region. In this embodiment, the laser chip has a light extraction efficiency greater than 0.25 mW/mA.

In a specific embodiment, the electroabsorption modulator has a length of from 75 microns to 250 microns.

In a specific embodiment, the cavity surface of the electroabsorption modulator is plated with an anti-reflection coating.

In a specific embodiment, the laser chip further includes a semiconductor optical amplifier; the semiconductor optical amplifier being located on a side of the electroabsorption modulator remote from the gain region and electrically isolated from the electroabsorption modulator; The active layer of the semiconductor optical amplifier is disposed in the same layer as the active layer of the multi-segment distributed feedback/distributed Bragg laser of the passive grating.

In a specific embodiment, the cavity surface of the semiconductor optical amplifier is plated with an anti-reflection film. And in a specific arrangement, the amplifier has a length of 50 micrometers to 300 micrometers.

In a specific embodiment, the laser is a distributed feedback/distributed Bragg laser of a quarter-wavelength phase shift grating. In this embodiment, the laser chip light extraction efficiency is greater than 0.15 mW/mA.

In a specific embodiment, the second trench extends across the multiple quantum well layer of the distributed feedback laser of the quarter-wavelength phase shift grating.

In a specific embodiment, the second trench has a cross section that is an inverted isosceles trapezoidal trench.

In a specific embodiment, the bottom surface of the second trench has a width of 2 to 100 microns and the trapezoidal bottom tilt angle is greater than 4 degrees from a right angle.

In a specific embodiment, the second trench is filled with inert particles. The isolation effect during isolation is further improved.

In a particular embodiment, the inert particles are proton or ruthenium particles. Further improve the electrical isolation effect.

In a second aspect, there is provided a light emitting component comprising the laser chip of any of the above.

In the above technical solution, the distributed feedback laser of the multi-segment distributed feedback/distributed Bragg laser or the quarter-wavelength phase shift grating using the passive grating is monolithically integrated with the monitoring photodiode, thereby reducing the cost of the entire laser chip. And the output power of the laser chip is improved.

In a third aspect, there is provided an optical module comprising the laser chip of any of the above or the above-described light emitting component.

A fourth aspect provides a network device, where the network device includes the optical module, where the network device is an optical line terminal or a network unit.

In a fifth aspect, a passive optical network system is provided. The passive optical network system includes an optical line terminal and an optical network unit, and at least one of the optical line terminal and the optical network unit includes the optical module.

DRAWINGS

1 is a schematic structural diagram of a laser chip according to an embodiment of the present application;

2 is a view showing a correspondence relationship between a grating reflection region length and a reflectance of the laser chip shown in FIG. 1;

FIG. 3 is a schematic structural diagram of another laser chip according to an embodiment of the present disclosure;

4 is a schematic structural diagram of another laser chip according to an embodiment of the present application;

FIG. 5 is a schematic structural diagram of another laser chip according to an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of another laser chip according to an embodiment of the present disclosure;

FIG. 7 is a corresponding relationship between a back reflectance of a monitoring photodiode and a second trench width according to an embodiment of the present application;

FIG. 8 is a diagram showing relationship between photocurrent of a photodiode and a laser output power according to an embodiment of the present application.

Detailed ways

The present invention will be further described in detail with reference to the accompanying drawings, in which FIG. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present application without departing from the inventive scope are the scope of the present application.

In order to facilitate the understanding of the laser chip provided by the embodiment of the present application, the laser chip provided by the embodiment of the present application is described in detail below with reference to the accompanying drawings and specific embodiments. First, as shown in FIG. 1 and FIG. The laser chip consists of two parts: a laser and a monitor photodiode 20. Wherein, the laser includes a gain region 12 and at least one grating reflection region, the gain region 12 is electrically isolated from each of the grating reflection regions, and at least one grating reflection region transmits a portion of the laser light emitted by the gain region 12 to the monitor photodiode 20; or A second trench 36 is disposed between the laser and the monitor photodiode 20, and is electrically isolated by the second trench 36, and a portion of the laser light emitted by the laser is transmitted to the monitor photodiode 20. In a specific arrangement, the laser may be a multi-segment distributed feedback/distributed Bragg laser 10 of a passive grating or a distributed feedback laser 80 of a quarter-wavelength phase shift grating, and the laser light emitted by the laser is partially transmitted to the monitoring photoelectric diode. The laser as shown in Fig. 1 is a multi-segment distributed feedback/distributed Bragg laser 10 of a passive grating; and the laser shown in Fig. 5 is a distributed feedback laser 80 of a quarter-wavelength phase shift grating. However, no matter which of the above lasers is used, the laser and the monitor photodiode 20 are prepared by monolithic integration during preparation, wherein the active layer 30 of the laser and the monitor photodiode 20 are disposed in the same layer, and are specific When set, the laser is electrically isolated from the monitor photodiode 20.

As shown in FIG. 1 and FIG. 5, when the lasers are different lasers, the structure of the corresponding laser chip is different. The laser chip provided by the embodiment of the present application is described in detail below with reference to the accompanying drawings.

First, the laser chip structure of the multi-segment distributed feedback/distributed Bragg laser 10 using a passive grating of a laser is described, which comprises a multi-segment distributed feedback/distributed Bragg laser 10 and a monitoring photodiode 20 of a two-part passive grating.

The multi-segment distributed feedback/distributed Bragg laser 10 of the passive grating comprises a multi-layer structure, as shown in FIG. 1 , which comprises an active layer 30 and a multiple quantum well interposed in the active layer 30 . The layer 40, and the respectively restricting the guiding layer 50 on both sides of the multiple quantum well layer 40; wherein, in a specific arrangement, the multi-segment direct limiting laser may not include respectively limiting the guiding layer 50, as shown in FIG. In the structure shown, the multi-segment direct confinement laser includes an active layer 30 and a multiple quantum well layer 40 disposed in the active layer 30. And when the multi-segment distributed feedback/distributed Bragg laser 10 adopts the structure as shown in FIG. 1 or FIG. 3, the multi-segment distributed feedback/distributed Bragg laser 10 includes three parts according to functions, and the laser chip placement direction shown in FIG. For the reference direction, from left to right, the three parts are: a first grating reflection area 11, a gain area 12, and a second grating reflection area, the second grating reflection area 13, and the monitoring photodiode 20 is adjacent to the second grating reflection area. The reflective region 13 and each portion share the same active layer 30 to form an integrated device. The first grating reflection area 11 and the second grating reflection area and the second grating reflection area 13 all adopt a uniform grating, so that it can be fabricated by a holographic exposure method suitable for mass production. In a specific setting, the grating period is 195 nm to 215 nm. Or between 235nm and 250nm. In a specific arrangement, the gain region 12 may or may not have a grating, and the grating period of the gain region 12 and the grating of the first grating reflection region 11 and the second grating reflection region 13 when having a grating The cycle is the same. And when there is a grating in the gain region 12, the laser is a distributed feedback semiconductor laser, and when the gain region 12 has no grating, the laser is a distributed Bragg laser.

In a specific arrangement, electrical isolation between the first grating reflection region 11, the gain region 12, and the second grating reflection region 13 and the monitor photodiode 20 is achieved by etching and ion implantation. As shown in FIG. 1 , a plurality of first trenches are disposed on the active layer 30 , and the number of the first trenches is three, respectively, a first trench a31 , a first trench b32 , and a first trench C33, the placement direction of the laser chip shown in FIG. 1 is a reference direction, and the arrangement order of the first trenches from left to right is: first grating reflection area 11, first groove a31, gain area 12, first The trench b32, the second grating reflection region 13, the first trench c33, and the monitor photodiode 20, that is, the three regions and the arrangement of the monitor photodiode 20 are: a first grating reflection region 11, a gain region 12, and a second The grating reflection region 13 and the monitor photodiode 20; and the electrical isolation of the first grating reflection region 11, the gain region 12, the second grating reflection region 13, and the monitor photodiode 20 are realized by the three first grooves provided. As shown in FIG. 1, the first trench a31 electrically isolates the first grating reflection region 11 from the gain region 12, and the first trench b32 electrically isolates the gain region 12 from the second grating reflection region 13, the first trench c33 The second grating reflection region 13 is electrically isolated from the monitor photodiode 20.

When the first trench a31, the first trench b32, and the first trench c33 are specifically disposed, as can be seen from FIG. 1, the depths of the first trench a31, the first trench b32, and the first trench c33 are The multi-quantum well layer 40 is not reached. In a specific arrangement, the first trench has a width of 10 to 30 micrometers (e.g., 10 micrometers, 15 micrometers, 20 micrometers, 30 micrometers) and a depth of 0.1 to 1 micrometer (e.g., 0.1 micron, 0.4 micron, 0.8 micron, 1 micron). And in order to improve the isolation effect, the first trench is filled with protons or inert ions, so that the isolation resistance is greater than 10 kilohms. The inert particles are specifically germanium, germanium or argon ions, etc. in the integrated device, the first grating reflection region 11 Both the second grating reflection region 13 serve as a passive grating reflection region. That is, only the gain region 12 injects current during operation, and no current is injected into the first grating reflection region 11 and the second grating reflection region 13. Since the gain current of the gain region 12 is large, the photon density in the cavity is high, and the first grating reflection region 11 and the second grating reflection region 13 can operate in a transparent carrier state, and the loss (about 20 cm-1) is relatively The gain (100 cm -1 ) of the first grating reflection region 11 and the second grating reflection region 13 is much smaller. Controlling the lengths of the first grating reflection region 11 and the second grating reflection region 13 and the pump current of the active layer 30, the first grating reflection region 11 and the second grating reflection region 13 can achieve a large reflectance, as shown in FIG. Shown is the relationship between the peak reflectivity of the grating reflection region and the length of the grating. As can be seen from Fig. 2, as the lengths of the first grating reflection region 11 and the second grating reflection region 13 increase, the corresponding reflectance also increases.

In order to obtain a large light output power, the reflectance of the first grating reflection region 11 should be less than 30%, usually less than 5%, and the antireflection film is plated at the front end of the gain region 12; the reflectance of the second grating reflection region 13 is greater than 80%. Thereby, 20% of the laser light of the gain region 12 penetrates through the second grating reflection region 13 to enter the monitor photodiode 20. The rear end surface of the gain region 12 can be equivalently plated with a high reflective film due to the second grating reflection region 13 and the monitor photodiode 20, and the length of the monitor photodiode 20 can be controlled, so that the light of the rear end surface can be absorbed by the monitor photodiode 20, thereby Eliminating the influence of the phase of the rear end face on the single mode of the laser, the single-mode yield of the device can be close to 100%, and the cost of the rear end coating is saved. In order to further improve the absorption effect. In a specific embodiment, the length of the first grating reflective region 11 is less than 100 microns. Gain region 12 is greater than 50 microns in length and less than 200 microns. Preferably, the length of the second grating reflection region 13 is greater than 100 microns. And the length of the monitor photodiode 20 is generally greater than 5 microns and less than 50 microns. For example, the length of the first grating reflection region 11 is 90 micrometers, the length of the gain region 12 is 100 micrometers, the length of the second grating reflection region 13 is 150 micrometers, and the length of the monitor diode 20 is 150 micrometers.

The integrated device proposed in the embodiment of the present application fully combines the advantages of the distributed feedback Bragg laser and the DFB laser: the single-mode opposite phase of the laser is insensitive, can achieve high single-mode yield and high-power operation at the same time, and can simultaneously monitor the light output. The size of the power.

Controlling the length of the first grating reflection region 11 can make the mirror loss of the laser small and reduce the threshold gain; since the relaxation oscillation frequency of the laser is inversely proportional to the root number of the active layer 30, a short gain region is used. 12 can achieve a large modulation bandwidth (greater than 50 micrometers, less than 200 micrometers), and the embodiment of the present application is applicable not only to 10G PON but also to NG-PON2.

As can be seen from the above description, in the preparation of the laser chip, since the multi-segment distributed feedback/distributed Bragg laser 10 of the passive grating is a laser diode, and the monitoring photodiode 20 is also a diode structure, it can be prepared at the time of preparation. Monolithic integration, electrically isolating the two devices by providing a first trench, so that monolithic integration of the laser and the monitor photodiode 20 does not add additional manufacturing difficulty and cost to the device. The use of a single chip integrated backlight detector in a light emitting assembly can reduce the cost of the light emitting component, respectively.

As shown in FIG. 4, FIG. 4 is a modified structure of the laser chip shown in FIG. 1. The structure of the laser chip shown in FIG. 4 includes: a laser and a monitor photodiode 20, and the laser is a multi-segment distribution of a passive grating. a feedback/distribution Bragg laser 10; the multi-segment distributed feedback/distributed Bragg laser 10 of the passive grating includes: a gain region 12 and a second grating reflection region 13; and in a specific arrangement, the laser chip further includes an electroabsorption modulator 60 Wherein the monitor photodiode 20 is located on a side of the second grating reflection region 13 away from the gain region 12; the electro-absorption modulator 60 is located on a side of the gain region 12 remote from the monitor photodiode 20 and is electrically isolated from the gain region 12. When specifically prepared, the electroabsorption modulator 60 has a length of from 75 microns to 250 microns, such as 75 microns, 100 microns, 150 microns, 200 microns, 250 microns.

When the isolation is specifically implemented, as shown in FIG. 4, the first trench is disposed on the active layer 30. In the embodiment of the present application, three first trenches are disposed: the first trench d34, the first trench a trench b32 and a first trench c33, wherein the direction of placement of the laser chip shown in FIG. 4 is a reference direction, from left to right: electro-absorption modulator 60, first trench d34, gain region 12, a trench b32, a second grating reflective region 13, a first trench c33 and a monitor photodiode 20; wherein the first trench d34 isolates the electro-absorption modulator 60 from the gain region 12, the first trench b32 will have a gain region 12 is isolated from the second grating reflection region 13; the first trench c33 isolates the second grating reflection region 13 from the monitor photodiode 20.

When the first trench d34, the first trench b32, and the first trench c33 are specifically disposed, as can be seen from FIG. 4, the depths of the first trench d34, the first trench b32, and the first trench c33 are The multi-quantum well layer 40 is not reached, and in order to improve the isolation effect, the first trench is filled with a proton or an inert ion, and the inert particle is specifically a germanium, a germanium or an argon ion, etc., in the laser chip provided in the embodiment of the present application, The front end of the multi-segment distributed feedback/distributed Bragg laser 10 of the passive grating integrates an electro-absorption modulator 60, and in a specific arrangement, the cavity surface of the electro-absorption modulator 60 is coated with an anti-reflection film. Therefore, the influence of the front facet phase on the direct modulation laser single mode property is substantially negligible; due to the presence of the monitor photodiode 20 and the second grating reflection region 13, the front facet phase is single mode to the laser. The impact can also be eliminated. And the laser chip light extraction efficiency is greater than 0.25 mW / mA.

As shown in FIG. 5, FIG. 5 shows another modified structure. In the laser chip structure shown in FIG. 5, the laser chip comprises: a semiconductor optical amplifier 70, an electroabsorption modulator 60, and a multi-segment of a passive grating. The feedback feedback/distribution Bragg laser 10 and the monitor photodiode 20 are distributed. Wherein, in a specific embodiment, the laser chip further includes a semiconductor optical amplifier 70; the semiconductor optical amplifier 70 is located on a side of the electro-absorption modulator 60 remote from the gain region 12 and is electrically isolated from the electro-absorption modulator 60. The semiconductor optical amplifier 70 has a length of 50 micrometers to 300 micrometers.

In a specific arrangement, the isolation of the component is achieved by the first trench. As shown in FIG. 5, a plurality of first trenches are disposed on the active layer 30: a first trench e35, a first trench d34, and a first The trench b32 and the first trench c33; the laser chip placement direction shown in FIG. 5 is a reference direction, and from left to right: a semiconductor optical amplifier 70, a first trench e35, an electroabsorption modulator 60, and a first a trench d34, a gain region 12, a first trench b32, a second grating reflective region 13, a first trench c33, and a monitor photodiode 20; wherein the first trench will be the semiconductor optical amplifier 70 and the electro-absorption modulator 60, The first trench d34 isolates the electro-absorption modulator 60 from the gain region 12, the first trench b32 isolating the gain region 12 from the second grating reflection region 13; the first trench c33 is the second grating reflection region 13 and the monitor photoelectric The diode 20 is isolated.

In order to improve the effect of the isolation, protons or inert ions are implanted into the first trench, and the inert particles are specifically ruthenium, osmium or argon ions.

As shown in FIGS. 4 and 5, in order to simplify the device fabrication process, the integration of the electro-absorption modulator 60 or the electro-absorption modulator 60/semiconductor optical amplifier 70 with the electro-absorption modulator 60, the active layer 30 of the semiconductor optical amplifier 70 The material is the same as the multi-segment distributed feedback/distributed Bragg laser 10 and the electro-absorption modulator 60 of the passive grating, and the materials of the active layer 30 of the electro-absorption modulator 60 may be the same or different. For the integration of the electro-absorption modulator 60 and the monitoring photodiode 20, in order to increase the optical power, it is generally required to separately optimize the multi-segment distributed feedback/distributed Bragg laser 10 and the electro-absorption modulator 60 of the passive grating, and the electro-absorption modulator 60 and The active layer 30 of the multi-segment distributed feedback/distributed Bragg laser 10 of the source grating is different in material, and the integration of the two can be achieved by means of butt growth or selective epitaxy.

As shown in FIG. 6, FIG. 6 shows another laser chip including a laser and a monitor photodiode 20; wherein the laser is a distributed feedback laser 80 of a quarter-wavelength phase shift grating, and four points A distributed feedback laser 80 of one wavelength phase shift grating is electrically isolated from the monitor photodiode 20 by a second trench 36.

As shown in FIG. 6, the laser chip is monolithically integrated by a distributed feedback laser 80 of a quarter-wavelength phase shift grating and a monitor photodiode 20, and a second trench 36 is provided between the laser and the monitor photodiode 20, and passes through The second trench 36 is electrically isolated and a portion of the laser light emitted by the laser is transmitted to the monitor photodiode 20. The monitor photodiode 20 is adjacent to the rear end region of the distributed feedback laser 80 of the quarter-wavelength phase shift grating, and the distributed feedback laser 80 of the monitor photodiode 20 and the quarter-wavelength phase shift grating share the same active layer 30 to form an integration. Device. The distributed feedback laser of the quarter-wavelength phase-shifted grating is coated with an antireflection coating on the front end of the light-emitting surface, and the electrical isolation between the distributed feedback laser 80 of the quarter-wavelength phase-shifted grating and the monitor photodiode 20 is etched through the active layer. 30 is realized. As shown in FIG. 6, the second trench 36 is etched on the active layer 30. In a specific arrangement, the second trench 36 has an inverted isosceles trapezoidal groove in cross section. And in a specific arrangement, the bottom surface of the second trench 36 has a width of 2 to 100 micrometers, such as 2 micrometers, 30 micrometers, 50 micrometers, 70 micrometers, 90 micrometers, 100 micrometers, etc., and any width between 2 and 100 micrometers. . In addition, the trapezoidal bottom inclination angle deviates from the right angle angle by more than 4 degrees, such as 10 degrees, 15 degrees, and the like.

When the second trench 36 as shown in FIG. 6 can be formed by dry etching, the typical dry etching has a waveguide angle of about 10 degrees, which can reduce the distribution feedback of the quarter-wavelength phase shift grating. Reflection of the rear end face of the laser 80. The reflection of the end face of the monitoring photodiode 20 is related to the angle between the waveguide and the width of the isolation region. As shown in FIG. 7, the reflectance of the monitoring photodiode 20 can be made less than 0.1% when β=8° C. The larger the width, the higher the coupling efficiency. Low; the larger β, the lower the coupling efficiency. The reflection of the rear end face of the photodiode 20 can be suppressed by increasing the length of the monitor photodiode 20. Since the entire integrated device can be equivalent to the distributed feedback laser 80 of the AR-AR quarter-wavelength phase shift grating, the single mode yield can be close to 100%, and the cost of the rear end coating is saved. And the laser chip light extraction efficiency is greater than 0.15mW / mA.

It should be noted that the grating involved in the present invention may be above the active layer 40 or below the active layer 40.

FIG. 8 is a graph showing the relationship between the photocurrent of the monitor photodiode 20 and the laser output power. It can be seen that the two are in a linear relationship, which proves the effectiveness of the laser chip provided by the embodiment of the present application.

In addition, an embodiment of the present application provides a light emitting component including the laser chip of any of the above. The laser chip is integrally formed with the monitor photodiode 20 by a distributed feedback laser 80 of a multi-segment distributed feedback/distributed Bragg laser 10 or a quarter-wavelength phase shift grating using a passive grating, thereby reducing the cost of the entire laser chip, and The output power of the laser chip is increased.

In addition, the embodiment of the present application provides an optical module, where the optical module includes the optical module of any one of the foregoing, and the network device is an optical line terminal or an optical network unit. The laser chip is integrally formed with the monitor photodiode 20 by a distributed feedback laser 80 of a multi-segment distributed feedback/distributed Bragg laser 10 or a quarter-wavelength phase shift grating using a passive grating, thereby reducing the cost of the entire laser chip, and The output power of the laser chip is increased.

In addition, the embodiment of the present application provides a passive optical network system network device, where the passive optical network system network device includes the laser chip of any of the above. The laser chip is integrally formed with the monitor photodiode 20 by a distributed feedback laser 80 of a multi-segment distributed feedback/distributed Bragg laser 10 or a quarter-wavelength phase shift grating using a passive grating, thereby reducing the cost of the entire laser chip, and The output power of the laser chip is increased.

The integrated device solution of the proposed laser and optical monitoring detector in the embodiments of the present application can be applied not only to a passive optical network, but also to a cost-sensitive 10G PON, and also to an optical module of an optical transmission network and a data center. The monolithic integration of the laser and the optical monitoring detector not only reduces the cost of the optical module, but also improves the stability and performance of the optical module.

The above is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application, and should cover Within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

Claims

A laser chip, comprising: a laser and a monitoring photodiode, wherein the laser and the monitoring photodiode are monolithically integrated integrated structures, and the active layer of the laser and the monitoring photodiode are in the same layer Providing; electrically isolating the laser from the monitoring photodiode; wherein

The laser includes a gain region and at least one grating reflection region, the gain region being electrically isolated from each of the grating reflection regions, at least one of the grating reflection regions transmitting a portion of the laser light emitted by the gain region to the monitoring Photodiode; or,

A second trench is disposed between the laser and the monitor photodiode, and is electrically isolated by the second trench, and a portion of the laser light emitted by the laser is transmitted to the monitor photodiode.
The laser chip according to claim 1, wherein the laser comprises a first grating reflection region, a gain region and a second grating reflection region which are sequentially electrically isolated, and the monitor photodiode is located at the second The side of the grating reflection region that faces away from the gain region.
The laser chip according to claim 1 or 2, wherein the active layer is provided with a plurality of first trenches spaced apart, the first grating reflection region, the gain region, and the second grating reflection The region and the monitoring photodiode are electrically isolated by the first trench.
The laser chip according to claim 3, wherein said first trench is filled with protons or inert ions.
The laser chip according to claim 3, wherein said gain region has a grating; and a grating period of said gain region is the same as a grating period of said first grating reflection region and said second grating reflection region.
The laser chip according to claim 3, wherein the gratings of the first grating reflection region and the second grating reflection region are uniform gratings.
The laser chip according to claim 1, wherein the laser comprises: the gain region and a second grating reflection region;

The monitoring photodiode is located at a side of the second grating reflection region away from the gain region;

The laser chip further includes an electroabsorption modulator;

The electroabsorption modulator is located on a side of the gain region remote from the monitor photodiode and is electrically isolated from the gain region.
The laser chip according to claim 7, wherein the cavity surface of the electroabsorption modulator is plated with an anti-reflection film.
A laser chip according to claim 7 or 8, wherein said laser chip further comprises a semiconductor optical amplifier; said semiconductor optical amplifier being located on a side of said electroabsorption modulator remote from said gain region and said Electro-absorption modulator is electrically isolated;

The active layer of the semiconductor optical amplifier is disposed in the same layer as the active layer of the multi-segment distributed feedback/distributed Bragg laser of the passive grating.
The laser chip of claim 1 wherein said laser is a distributed feedback laser of a quarter-wavelength phase shift grating.
The laser chip of claim 10 wherein said second trench extends across said multi-quantum well layer of said distributed feedback laser of said quarter-wavelength phase shift grating.
The laser chip according to claim 10, wherein the second trench has a cross section of an inverted isosceles trapezoidal trench.
The laser chip according to claim 10, wherein the second trench has a bottom surface width of 2 to 100 μm.
A light emitting device comprising the laser chip according to any one of claims 1 to 13.
An optical module comprising the laser chip according to any one of claims 1 to 13 or the light emitting device according to claim 14.
A network device, comprising the optical module according to claim 15, wherein the network device is an optical line terminal or an optical network unit.