CN113156592A

CN113156592A - Light emitting COC assembly and light emitting device

Info

Publication number: CN113156592A
Application number: CN202011639831.5A
Authority: CN
Inventors: 胡百泉; 李林科; 吴天书; 杨现文; 张健
Original assignee: Wuhan Linktel Technologies Co Ltd
Current assignee: Wuhan Linktel Technologies Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-07-23

Abstract

The invention relates to a light-emitting COC component, which comprises a high-resistance silicon substrate and a first high-resistance silicon carrier laid on the high-resistance silicon substrate, wherein the first high-resistance silicon carrier is provided with a metal ground on which an EML laser chip and a backlight detector chip which are obliquely arranged are arranged; the EML laser chip comprises a DFB area, an EAM modulation area and a waveguide area which are sequentially arranged along the direction of a light path. A light emitting device is also provided comprising at least one light emitting COC component as described above. The invention adopts high-resistance silicon as a substrate to form full silicon-based packaging, and optical elements are all integrated and packaged on the high-resistance silicon-based; high-frequency signal wiring is prepared on the high-resistance silicon substrate, so that low loss of high-frequency signals is met; the optical element adopts full-high-resistance silicon materials, the laser chip adopts inclined waveguide and the chip is obliquely mounted, the optical element is obliquely arranged, the waveguide is obliquely arranged, the requirement of the optical component on ultralow echo is met, the device has the advantages of simple structure, easy control of a coupling method and the like, and has the advantages of small occupied space, easy assembly and the like.

Description

Light emitting COC assembly and light emitting device

Technical Field

The invention relates to the technical field of optical devices, in particular to a light-emitting COC component and a light-emitting device.

Background

For multi-channel parallel light emitting devices/light assemblies, the multi-channel parallel light emitting devices/light assemblies are mainly used in scenes with the speed of 40Gpbs or more, such as 40G, 100G, 200G, 400G and other applications. Due to the multi-channel light emitting device, the power consumption of the device is correspondingly increased, and especially for long-distance EML type transmission, the heat dissipation requirement of the device is more and more strict. The heat dissipation of the device is realized by adopting a semiconductor cooler TEC for temperature control in one direction, adopting a material with good heat dissipation in the other direction and adopting a good heat dissipation structure in the other direction. Materials that dissipate heat well are typically AlN ceramics, tungsten copper metal, silicon wafers, and heat dissipation structures are not operable in much manner inside the device or inside the assembly, typically increasing the heat dissipation area. These modes of use are usually discrete, i.e. chip on ceramic, ceramic on tungsten copper or silicon, and this assembly mode has many processes, and the deviation of operation precision increases in turn, such as CN201210154342, CN201610316060, CN201721807257, etc.

In addition, with the improvement of the transmission rate of the optical module and the optical device, for the rate of a single wave above 50Gpbs, the laser chip is very sensitive to the echo inside and outside the component, and the echo interferes with the normal stable modulation signal of the laser chip, so that the high-frequency performance of the emitted light component/device is degraded. A common way of shielding or reducing the echo is to add isolators, optical element surface tilt. However, the isolation of the existing isolator is usually only 20dB, even if the isolation of the bipolar isolator is difficult to achieve the full-wave band 30dB or the inclination of the optical surface, and for the optical element far away from the laser chip, such as CN201810926181.9 CN201910770605.1, the reflection of the inclined surface of the MUX assembly in the patent can avoid returning to the laser chip, whereas in these comparison patents, the reflection of the lens close to the laser chip, such as the lens, is less than 0.2mm, especially for the plano-convex lens, and the planar lens reflection directly returns to the laser. On the other hand, the laser chip itself is mostly planar, such as CN201720678133.3, the surface of the chip is perpendicular to the waveguide, but an antireflection film is usually added on the surface to reduce reflection, but this approach is not enough for the optical component with higher speed, although it is feasible for the optical device with low speed, and its reflectivity is still higher than 0.1%, i.e. 30dB echo, which is not enough for the high frequency with speed above 50 Gpbs.

For optical structures of optical devices/components, mostly free space optical paths, free space optics has the advantages of flexibility, the possibility of arranging a plurality of elements with independent functions, and relative maturity of the elements. However, with the increasing transmission capacity of the optical module, the transmission channels of the optical device are more and more, and have been developed from a single channel to a special application of 4 channels, 8 channels, and even 16 channels, while the size of the optical module is smaller and smaller under the requirements of performance and power consumption, so the size of the optical device/component is also smaller and smaller, but the density of elements inside the device is larger and larger, and the occupied space is large for a free space optical path; the optical device/component of the waveguide integration scheme adopts the waveguide element, and the waveguide with high refractive index difference can realize great reduction of the size of the waveguide. However, the isolators in waveguide integration schemes have not been mature. In addition, the conventional silicon material has large high-frequency loss when used for high-frequency signal transmission, and cannot perform high-frequency transmission. How to solve the echo problem of the laser, assembly, high frequency design, etc. without the isolator is a problem.

Disclosure of Invention

It is an object of the present invention to provide a light emitting COC component and a light emitting device that address at least some of the deficiencies of the prior art.

In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions: a light emission COC component comprises a high-resistance silicon substrate and a first high-resistance silicon carrier laid on the high-resistance silicon substrate, wherein a metal ground is arranged on the first high-resistance silicon carrier, and an EML laser chip and a backlight detector chip which are obliquely arranged are arranged on the metal ground; the EML laser chip comprises a DFB area, an EAM modulation area and a waveguide area which are sequentially arranged along the direction of a light path.

Furthermore, the waveguide is obliquely arranged in the waveguide area, and the light-emitting surface of the waveguide, which is far away from the DFB area, is expanded to form a horn mouth.

Further, the waveguide region comprises a first core waveguide and a cladding layer covering the first core waveguide, and the first core waveguide and the cladding layer both adopt small doping.

Further, the EAM modulation region includes a second core waveguide, and a thickness of the first core waveguide is greater than a thickness of the second core waveguide.

Furthermore, a high-frequency wiring is arranged below the EML laser chip.

The embodiment of the invention provides another technical scheme: a light emitting device comprising at least one light emitting COC component as described above.

Further, the light-emitting COC component has a plurality of light-emitting COC components, and the plurality of light-emitting COC components are combined into one ground through their respective metal grounds.

The optical fiber isolation structure further comprises a lens group, an isolation group, a transition waveguide area and a tail fiber area which are sequentially arranged along the direction of an optical path, wherein the lens group, the isolation group, the transition waveguide area and the tail fiber area are all arranged on a common substrate.

Further, the substrate comprises a reference ground, a second high-resistance silicon carrier for the light emission COC component to be arranged, a lens groove for the lens group and the isolation group to be arranged, a waveguide core layer and a cladding layer which are located in the transition waveguide area, an air gap for the refractive index matching glue to be arranged, and a V groove which is located in the tail fiber area.

Further, the transition waveguide region comprises an inclined waveguide, a curved waveguide and a horizontal waveguide which are sequentially arranged along the light path direction, and the curved waveguide is a transition radian waveguide of the inclined waveguide and the horizontal waveguide.

Compared with the prior art, the invention has the beneficial effects that: forming a full silicon-based package by using high-resistance silicon as a base material, and integrally packaging all optical elements on the high-resistance silicon-based package; high-frequency signal wiring is prepared on the high-resistance silicon substrate, so that low loss of high-frequency signals is met; the optical element adopts full-high-resistance silicon materials, the laser chip adopts inclined waveguide and chip inclined mounting, the optical element is arranged in an inclined mode, the waveguide is arranged in an inclined mode, the requirement of ultralow echo of the optical component is met, and meanwhile the device has the advantages of being simple in structure, easy to control a coupling method and the like, and has the advantages of being small in occupied space, easy to assemble and the like.

Drawings

FIG. 1 is a top view of a light emitting COC assembly according to an embodiment of the present invention;

FIG. 2 is a side view of a light emitting COC assembly provided by an embodiment of the present invention;

fig. 3 is a top view of an EML laser chip of a light emitting COC package according to an embodiment of the present invention;

fig. 4 is a schematic cross-sectional view of an EML laser chip of an optical transmit COC module according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a light-emitting surface optical path of an EML laser chip of the light-emitting COC component according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a four-channel light emitting COC module according to an embodiment of the present invention;

fig. 7 is a top view of a light emitting device provided by an embodiment of the present invention;

fig. 8 is a side view of a light emitting device provided by an embodiment of the present invention;

fig. 9 is a schematic structural view of a substrate of a light emitting device according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of an isolated group of light emitting devices provided by an embodiment of the present invention;

FIG. 11 is a schematic diagram of a transition waveguide region of a light emitting device according to an embodiment of the present invention;

fig. 12 is a schematic cross-sectional view of a pigtail region of a light emitting device according to an embodiment of the invention.

Detailed Description

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

The first embodiment is as follows:

referring to fig. 1 to 6, an embodiment of the invention provides a light emitting COC component, including a high-resistance silicon substrate 101 and a first high-resistance silicon carrier 103 laid on the high-resistance silicon substrate 101, wherein a metal ground 110 is provided on the first high-resistance silicon carrier 103, and an EML laser chip 102 and a backlight detector chip 108 both obliquely arranged are disposed on the metal ground 110; the EML laser chip 102 includes a DFB region 301, an EAM modulation region 302, and a waveguide region 303 sequentially arranged along an optical path direction. Preferably, the waveguide region 303 has a waveguide 304 disposed obliquely therein, and the waveguide 304 expands to form a bell mouth away from the light exit surface of the DFB region 301. A high-frequency wire is arranged below the EML laser chip 102. Preferably, the device further includes a matching resistor 105, a first capacitor 106, and a second capacitor 107, the matching resistor 105 is connected in parallel with the EML, and the matching resistor 105, the first capacitor 106, and the second capacitor 107 are all disposed on the metal ground 110. In the embodiment, high-resistance silicon is used as a substrate to form a full silicon-based package, and all optical elements are integrated and packaged on the high-resistance silicon-based package; the optical element adopts a full-high-resistance silicon material, the laser chip adopts the inclined waveguide 304 and the chip is obliquely mounted, the optical element is obliquely arranged, the waveguide 304 is obliquely arranged, the requirement of the optical component on ultra-low echo is met, and meanwhile, the device has the advantages of simple structure, easy control of a coupling method and the like, and has the advantages of small occupied space, easy assembly and the like; high-frequency signal wiring is prepared on the high-resistance silicon substrate, and low loss of high-frequency signals is met. Specifically, the EML laser chip 102 is fixed above the metal ground 110 by eutectic method, and is located at the right side of the COC component 701, wherein the metal ground 110 can be divided into three blocks according to regions, which are respectively identified by the reference numerals 110-1, 110-2 and 110-3. A 50 ohm matching resistor 105 is arranged above the EML laser chip 102, the 50 ohm matching resistor 105 and the EML laser chip 102 are connected in parallel on a circuit and are interconnected with an EAM pad of the EML laser chip 102 through gold wire bonding, a first capacitor 106 is arranged on the left side of the 50 ohm matching resistor 105, and a second capacitor 107 is arranged on the left side of the first capacitor 106. On the left side of the EML laser chip 102 is a backlight detector chip 108, and the backlight detector chip 108 is disposed at an inclination angle larger than 8 degrees. The high-frequency wiring is arranged below the EML laser chip 102, the line width and the interval of the high-frequency wiring are related to the material, the thickness and the frequency of high-resistance silicon, and the line width and the interval are calculated through high-frequency simulation software so as to meet the requirement of 50 ohm characteristic impedance. The EML laser chip 102, the 50 ohm matching resistor 105, the first capacitor 106, the second capacitor 107, and the backlight detector chip 108 are all disposed above the metal ground 110. In addition, a metal reference ground 104 is provided between the first high resistance silicon substrate 101 and the high resistance silicon carrier 103. The metal reference ground 104 may be formed by growing the first high-resistance silicon carrier 103 again above the metal reference ground 104 after a metal layer is grown by evaporation or the like; or a metal layer is evaporated at the bottom of the single first high-resistance silicon carrier 103, a metal layer is evaporated at the top of the high-resistance silicon substrate 101, and then the two metal layers are fixed in a sintering mode, or a later-stage metal adhesive high-temperature curing mode is adopted for fixing. The metal reference ground 104 and the metal ground 110 are electrically connected by a via hole (not shown), and the via hole is punched by laser etching and then filled by a metal deposition process. The signal transmission line 109 is connected to an external device.

As an optimized solution of the embodiment of the present invention, please refer to fig. 3 and 4, the waveguide region 303 has a waveguide 304 disposed obliquely therein, and the waveguide 304 extends to form a bell mouth away from the light emitting surface of the DFB region 301. The waveguide region 303 includes a first core waveguide 401 and a cladding 402 that wraps the first core waveguide 401, and the first core waveguide 401 and the cladding 402 both use small doping. The EAM modulation region 302 comprises a second core waveguide 403, the first core waveguide 401 having a thickness greater than a thickness of the second core waveguide 403. In the present embodiment, the EML laser chip 102 is mounted with a tilt angle that depends on the tilt angle of the waveguide 304 in the waveguide region 303 of the EML laser chip 102. The EML laser chip 102 comprises three functional regions, a DFB region 301, an EAM modulation region 302 and a waveguide region 303, a waveguide 304 is arranged near the center of the waveguide region 303, the waveguide 304 expands in a bell mouth shape at a position close to a right light-emitting surface of the EML laser chip 102, meanwhile, small doping is adopted for a core layer waveguide 401 and a cladding layer 402 of the waveguide region 303, small refractive index difference is formed, meanwhile, the thickness of the core layer waveguide 401 is larger than that of a core layer waveguide 403 of the EAM region, and the size of a single-mode module of the waveguide 304 is enlarged in the fast axis direction and the slow axis direction, so that a small divergence angle is obtained; in addition, the chip waveguide 304 is designed to only present a single polarization mode, i.e., TE mode or TM mode, in the waveguide 304. And a water vapor-proof passivation film and an antireflection film 404 are arranged on the right end face of the chip. In addition, as shown in fig. 5, the inclination angle between the waveguide 304 and the end surface 501 at the right end surface of the EML laser chip 102 satisfies two conditions, that the emergent light satisfies a small horizontal angle, the emergent light beam is reflected by the optical element surface 502 at the right side of the chip, the reflected light deviates from the waveguide area of the chip, and the angle of the reflected light in the waveguide after returning to the waveguide is larger than the total reflection angle of the waveguide, so as to form a radiation mode.

Example two:

referring to fig. 1 to 12, a light emitting device includes at least one light emitting COC element 701 as described above. Preferably, there are a plurality of the light emitting COC components 701, and the plurality of the light emitting COC components 701 are combined into one ground through their respective metal grounds 110. In this embodiment, referring to fig. 6, for a four-channel COC component 701, four channels are arranged side by side at equal intervals, metal grounds 110 on the upper surface of a silicon substrate carrier are combined into a ground, and a reference ground is combined into a large reference ground. The four EML laser chips 102 are located in the same plane. The four EML laser chips 102 are tilted at the same angle.

As an optimized solution of the embodiment of the present invention, please refer to fig. 7, fig. 8, and fig. 9, the light emitting device further includes a lens group 702, an isolation group 703, a transition waveguide region 704, and a pigtail region 705, which are sequentially arranged along the optical path direction, and the lens group 702, the isolation group 703, the transition waveguide region 704, and the pigtail region 705 are all disposed on a common substrate. Preferably, the substrate comprises a reference ground 801, a second high-resistance silicon carrier 802 for the light emission COC component 701 to be arranged, a lens group 702 for the lens group and the isolation group 703, a core 803 and cladding 804 of the waveguide 304 in the transition waveguide region 704, an air gap 807 for an index matching glue 706, and a V-groove 805 in the pigtail region 705. In this embodiment, the COC component 701 is located at the leftmost side, the light emitting direction of the EML laser chip 102 faces to the right side, a lens group 702 is located at the right side of the COC component 701, each EML laser chip 102 corresponds to one lens, and the optical axis of the lens is aligned with the light emitting direction of the EML laser chip 102. An isolation group 703 is arranged on the right side of the lens group 702, a transition waveguide region 704 is arranged on the right side of the isolation group 703, the transition waveguide region 704 is a tail fiber region 705, an air gap of about 50um is arranged between the transition waveguide region 704 and the tail fiber region 705, and a refractive index matching glue 706 meeting the requirements of the waveguide 304 and the optical fiber is filled in the air gap. The COC assembly 701, lens group 702, isolation group 703, transition waveguide region 704, pigtail region 705, and index matching glue 706 are all disposed on a common substrate, which is disposed above TEC 707. In addition, the substrate 708 is formed as follows: growing a metal layer, which can be a metal film such as copper, gold and the like, on the substrate COC region by using a mask technology, and forming a regional metal layer at the moment; continuing to grow silicon on the substrate and the metal layer, wherein the growth height meets the design thickness of the COC; growing SiO in transition waveguide region and tail fiber region by using mask technology₂A core layer; in SiO₂Growing SiO on the core layer₂The growth height of the cladding meets the design height of a tail fiber V groove; growing a gold layer on the upper surface and signal wiring in the COC area by using a mask technology; laser etching or electron beam etching the lens groove and the air gap; etching the V-shaped groove by laser or electron beams; thinning; cutting and cleaning.

Referring to fig. 8, as an optimized scheme of the embodiment of the present invention, the optical fibers of the EML laser chip, the lens group 702, the isolation group 703, the transition waveguide region 704, and the pigtail region 705 are located in the same optical plane. The EML laser chip is a separately prepared chip, and may be an InGaAsP material type chip or an InP material type chip. The lens group 702 is a silicon lens made of the same material as the substrate, the silicon lens is a convergent lens, generally a plano-convex lens, the convex surface is spherical or aspheric, the convex surface faces the direction of the EML laser chip, and the silicon lens is cured in a lens groove on the substrate by ultraviolet dual-curing adhesive after online active coupling. As shown in fig. 10, the isolation group 703 is formed by gluing three elements, the leftmost element is a triangular prism 901, the middle element is a polarizer 902, the rightmost element is a 1/4 wave plate 903, the heights of the polarizer 902 and the 1/4 wave plate 903 are both smaller than that of the triangular prism 901 in the vertical direction, the triangular prism 901 is made of silicon which is the same as the substrate, and after passive identification by a high-precision chip mounter, ultraviolet dual-curing glue is used for curing in a lens groove on the substrate. The isolation group 703 plays two main roles, one is used to isolate the backward light at the left end face of the transition waveguide region, and the principle is: the EML laser chip emits horizontal linearly polarized light, the transmission direction of the polarizer is parallel to the horizontal direction, the linearly polarized light emitted by the EML laser chip transmits through the triangular prism 901 and the polarizer 902 and then transmits through the 1/4 wave plate to become circularly polarized light, the circularly polarized light reaches the left end face 904 of the transition waveguide region and then is reflected a little, and after reflection, the circularly polarized light transmits through the 1/4 wave plate to become vertical linearly polarized light and cannot transmit through the polarizer; the other function is that the triangular prism 901 deflects the incident oblique light beam to form an angle 905 and a transverse offset 906, the angle 905 and an angle 1101 of the oblique waveguide of the waveguide in the transition waveguide region are refraction angles, the angle 1101 meets the condition that the reverse light in the waveguide is a radiation mode field, and the transverse offset 906 is used for adjusting the transverse displacement of the waveguide, an EML laser chip and a lens group, so that the spatial arrangement of the optical component is more flexible. The polarizer +1/4 wave plate combination in the isolation group 703 can be replaced by the polarizer with magnetic ring + Faraday crystal + analyzer form.

As an optimized scheme of the embodiment of the present invention, please refer to fig. 11 and 12, a transmission direction of a light beam emitted from the isolation group 703 is obliquely incident to a left end face 904 of the transition waveguide region 704, an incident angle is 905, the transition waveguide region is composed of three waveguides and two surfaces, the left end face 904, the inclined waveguide 1001, the curved waveguide 1002, the horizontal waveguide 1003 and the right end face 1004 are sequentially arranged from left to right, and the curved waveguide 1003 is a natural transition arc waveguide of the inclined waveguide 1001 and the horizontal waveguide 1002 to reduce loss. The tilt angle 1101 of the tilted waveguide 1001 is in fresnel refraction angle relationship with the angle 905. The tilt angle 1101 is a specific angle calculated when there is a tilt angleWhen stray light is input from the right side of the waveguide, the light does not satisfy the total reflection angle any more after reversely returning to the waveguide at the left end face 904, and a radiation mode is formed, so that good return loss is obtained. The input end face 904 and the output end face 1004 are both planar for ease of machining. The inclined waveguide 1001, the curved waveguide 1002 and the horizontal waveguide 1003 are low-refractive-index SiO grown on a silicon substrate₂The single mode waveguide is designed to have a single mode field matching that of a single mode fiber to improve alignment tolerances. Referring to fig. 12, the tail fiber region includes a lower V-groove 1201, an optical fiber 1202, and an upper V-groove cover 1203, wherein silica gel is filled between the optical fiber and the V-groove, and the lower V-groove 1201 and the upper V-groove cover 1203 are bonded and cured by the silica gel. As shown in fig. eight, the fiber extends out of the V-groove 1201 with the fiber end face in the air gap at a distance of about 10-20um from the transition waveguide right end face 1004. And filling the air gap with refractive index matching glue to reduce the reflection of the optical fiber and the end face of the waveguide. The light beam transmission path of the whole optical assembly is that the light emitted by the EML is converged by the lens, then passes through the isolation group 703, enters the transition waveguide region 704, and is coupled into the optical fiber of the pigtail region 705 after being transmitted in the waveguide region. Because the laser chip emergent waveguide is subjected to expansion processing, the emission angle is smaller, the laser mode field radius is large, the coupling efficiency with the transition waveguide is high, the refractive index of the transition waveguide is matched with that of the optical fiber, and the coupling insertion loss of the transition waveguide and the optical fiber is less than 0.2dB, so that the whole device can obtain high optical coupling efficiency.

The invention can be applied to CWDM and LWDM wavelengths, and can be packaged in QSFP28, QSFP DD, OSFP and other modules.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A light emitting COC component, comprising: the high-resistance silicon laser device comprises a high-resistance silicon substrate and a first high-resistance silicon carrier laid on the high-resistance silicon substrate, wherein a metal ground is arranged on the first high-resistance silicon carrier, and an EML laser chip and a backlight detector chip which are obliquely arranged are arranged on the metal ground; the EML laser chip comprises a DFB area, an EAM modulation area and a waveguide area which are sequentially arranged along the direction of a light path.

2. The light-emissive COC assembly of claim 1, wherein: the waveguide area is internally provided with a waveguide which is obliquely arranged, and the waveguide is expanded to form a horn mouth at the light-emitting surface far away from the DFB area.

3. The light-emissive COC assembly of claim 1, wherein: the waveguide region comprises a first core layer waveguide and a cladding layer which wraps the first core layer waveguide, and the first core layer waveguide and the cladding layer are both doped with small impurities.

4. A light emitting COC component according to claim 3, wherein: the EAM modulation region includes a second core waveguide, and a thickness of the first core waveguide is greater than a thickness of the second core waveguide.

5. The light-emissive COC assembly of claim 1, wherein: and a high-frequency wiring is arranged below the EML laser chip.

6. A light emitting device, characterized by: comprising at least one light-emissive COC component according to any of claims 1 to 5.

7. The light emitting device of claim 6, wherein: the light-emitting COC component is provided with a plurality of light-emitting COC components, and the plurality of light-emitting COC components are combined into a ground through respective metal grounds.

8. The light emitting device of claim 6, wherein: the optical fiber isolation device is characterized by further comprising a lens group, an isolation group, a transition waveguide area and a tail fiber area which are sequentially arranged along the direction of a light path, wherein the lens group, the isolation group, the transition waveguide area and the tail fiber area are all arranged on a common substrate.

9. The light emitting device of claim 8, wherein: the substrate comprises a reference ground, a second high-resistance silicon carrier for arranging the light-emitting COC assembly, a lens groove for arranging the lens group and the isolation group, a waveguide core layer and a cladding layer which are positioned in the transition waveguide area, an air gap for arranging refractive index matching glue and a V groove arranged in the tail fiber area.

10. The light emitting device of claim 8, wherein: the transition waveguide area comprises an inclined waveguide, a bent waveguide and a horizontal waveguide which are sequentially arranged along the direction of a light path, and the bent waveguide is a transition radian waveguide of the inclined waveguide and the horizontal waveguide.