923 results about "Quantum well" patented technology

The present disclosure provides a semiconductor green laser. The semiconductor green laser, from bottom to top, comprising a substrate, a lower limiting layer, a lower waveguide layer, an active layer, an upper waveguide layer, and an upper limiting layer. The active layer is a quantum well composed of well layers and barrier layers. Each of the well layers includes any one of AlInGaN, AlInN, AlGaN, AlN, InN, InGaN, and GaN, or any combination thereof. Each of the barrier layers includes any one of AlInGaN, AlInN, AlGaN, AlN, InN, InGaN, and GaN, or any combination thereof. An electron effective mass of each of the well layers is less than an electron effective mass of each of the barrier layers. A spontaneous polarization coefficient of each of the well layers is less than a spontaneous polarization coefficient of each of the barrier layers.

The invention relates to the technical field of photoelectricity, and discloses a full-spectrum LED epitaxial wafer, a preparation method thereof and an LED chip, the epitaxial wafer comprises a substrate, and the substrate is sequentially provided with a buffer layer, an N-type GaN layer, a multispectral light-emitting well layer and a P-type GaN layer; the multispectral light-emitting well layer comprises a first light-emitting well layer, a second light-emitting well layer and a third light-emitting well layer which are stacked in sequence, the first light-emitting well layer comprises a plurality of groups of InxGa (1-x) N quantum well layers, AlaGa (1-a) N interface layers and first GaN quantum barrier layers which are stacked in sequence, the second light-emitting well layer comprises a plurality of groups of InyGa (1-y) N quantum well layers, AlbGa (1-b) N interface layers and second GaN quantum barrier layers which are stacked in sequence, and the third light-emitting well layer comprises a plurality of groups of InzGa (1-z) N quantum well layers, AlcGa (1-c) N interface layers and third GaN quantum barrier layers which are stacked in sequence. According to the full-spectrum LED epitaxial wafer provided by the invention, the luminous efficiency and the color rendering index of a full-spectrum chip can be improved.

The invention provides a distributed feedback laser with a double-layer grating structure, and relates to the technical field of lasers, the laser forms an InGaAlAs multi-quantum well active region, an upper sampling grating layer and a lower phase shift grating layer on an n-type InP substrate in sequence, the upper grating layer is designed based on a reconstruction equivalent chirp technology, and the lower phase shift grating layer is designed based on a reconstruction equivalent chirp technology. Two sections of asymmetric modulation areas with sampling periods linearly gradually changing in opposite directions are arranged in the axial direction of the resonant cavity, and the lower grating layer is a quarter-wave phase shift grating matched with the period of the upper seed grating. Through the synergistic effect of equivalent phase modulation and phase shift generated by the double-layer grating, the photon density distribution in the cavity can be improved, the longitudinal space hole burning effect can be weakened, the sensitivity to end face phase fluctuation can be reduced, high single-mode power and large modulation bandwidth can be realized in a wide temperature range, and the double-layer grating is suitable for a high-speed optical communication and coarse wavelength division multiplexing transmission system.

A device (1) for emitting light, the device (1) comprising: a substrate (2); abase layer (4) arranged on the substrate (2); a diode layer structure (10) arranged on the base layer (4), the diode layer structure (10) comprising a quantum well layer structure (30) sandwiched between an n-doped semiconductor layer (12) and a p-doped semiconductor layer (14); the quantum well layer structure (30) comprising a first (41) and second (42) quantum well, a first (51) and a second (52) proximal barrier layer, and a first (61) and a second (62) distal barrier layer, wherein the first (41) and second (42) quantum wells and the first (51) and second (52) proximal barrier layers are sandwiched between the first (61) and second (62) distal barrier layers

The invention relates to the technical field of laser chips, in particular to a wide-wavelength electro-absorption modulated laser chip and a preparation method and application thereof. According to the wide-wavelength electro-absorption modulated laser chip provided by the invention, a plurality of specific areas are divided on a substrate, a first modulator layer, a first front grating layer and a second modulator layer are sequentially arranged on the areas, and phosphorus ions are injected into the first modulator layer and the second modulator layer. The key sampling grating is arranged in the first front grating layer, the rear grating layer and the second front grating layer in an electron beam direct writing mode. A cladding layer and an electric contact layer are sequentially stacked above all the functional layers, an electric isolation trench is formed between the functional layers through etching, the uppermost layer is a P-surface electrode, and an N-surface electrode is arranged below the substrate. According to the chip, the same post-sampling grating reflection area is utilized, double-end modulation is integrated through the quantum well hybrid technology, the effects of double-end light emitting and rate and wavelength tuning performance doubling of the same integrated chip are achieved, and the power consumption of the integrated chip is greatly reduced.

Semiconductor light-emitting devices are provided, which includes a substrate, a Negative-type semiconductor, a quantum well, an electron-blocking layer, and a Positive-type semiconductor arranged in a sequential stack. The quantum well includes a first quantum well, a second quantum well, and a third quantum well. Optical parameters of the first quantum well, the second quantum well, and the third quantum well are distributed in a gradient in at least one direction. The quantum well includes a periodic structure consisting of a well layer and a barrier layer. A coefficient of thermal expansion of the well layer is smaller than or equal to that of the barrier layer. An elastic coefficient of the well layer is smaller than or equal to that of the barrier layer. A lattice constant of the well layer is greater than or equal to that of the barrier layer. A coefficient of spontaneous polarization of the well layer is smaller than or equal to that of spontaneous polarization of the barrier layer.

The invention relates to the technical field of semiconductor lasers, and discloses a semiconductor laser and a preparation method thereof, and the semiconductor laser comprises an epitaxial structure which comprises a substrate, a buffer layer, a lower limiting layer, a lower waveguide layer, a quantum well active layer, an upper waveguide layer, an upper limiting layer and an ohmic contact layer which are stacked from bottom to top; the back electrode is formed on the surface of one side, far away from the buffer layer, of the substrate; the side, close to the ohmic contact layer, of the epitaxial structure is etched to form a first current injection window, the etching end point of the first current injection window is the ohmic contact layer, and a plurality of suppression current injection structures are arranged in the edge area of the first current injection window at intervals in the first direction; and the front electrode is formed on the first current injection window and the plurality of suppression current injection structures. According to the invention, the thermal lens effect can be counteracted, a small far-field horizontal divergence angle can be realized, the temperature distribution of the current injection region can be uniform, and the reliability of the semiconductor laser can be improved.

The invention discloses an InGaN red light LED device based on a variable Al component electron barrier layer to enhance a polarization effect and a preparation method thereof. The InGaN red light LED device sequentially comprises a substrate, a low-temperature buffer layer, a high-temperature buffer layer, a non-doped GaN layer, an n-type doped GaN layer, a superlattice layer and / or a low-temperature GaN layer, a quantum well active region, a p-type AlGaN electron barrier layer and a p-type region from bottom to top, wherein the atomic percentage content of Al in the p-type AlGaN electron barrier layer is 22%-30%, and the thickness of the p-type AlGaN electron barrier layer is 5 nm to 15 nm. By controlling the p-type AlGaN electron barrier layer, long-wavelength emission of the low-In-component active region can be achieved, and the problems that a high-In-component active region of an existing long-wavelength InGaN red light LED is poor in crystal quality and difficult to obtain and the like are solved.

The invention provides a gallium-free antimonide semiconductor infrared laser, and belongs to the technical field of semiconductor lasers. A classical InGa (As) Sb-AlGaAsSb I type strained quantum well comprises three III group elements of In, Ga and Al and two V group elements of As and Sb. The valence band order of the structure is small, and the binding capacity to a hole is not high, so that the gain of the laser and the capacity of expanding to long wavelength are limited; comprising a GaSb substrate, and a lower cladding layer, a lower waveguide layer, an active region, an upper waveguide layer, an upper cladding layer and a protective layer which are sequentially epitaxially grown on the GaSb substrate, the lower cladding layer and the upper cladding layer are made of an AlAsy3Sb1-y3 material, y3 is greater than or equal to 0.02 and less than or equal to 0.22, quantum barriers of the lower waveguide layer, the upper waveguide layer and the active region are made of an Inx2Al1-x2Asy2Sb1-y2 material matched with the GaSb substrate, x2 is greater than or equal to 0.4 and less than or equal to 0.6, and y3 is greater than or equal to 0.02 and less than or equal to 0.22. A quantum well of the active region is made of an InAsy1Sb1-y1 material, wherein y1 is more than or equal to 0.50 and less than or equal to 0.85; the invention is applied to the antimonide semiconductor infrared laser.

The invention provides a multi-junction surface-emitting laser and a light-emitting module. A first reflecting layer, an active region and a second reflecting layer are sequentially stacked on a substrate, the active region is composed of at least two PN junctions or P-I-N junctions, and the PN junctions or the P-I-N junctions are connected through tunnel junctions; wherein the material of the substrate is gallium arsenide or indium phosphide, the crystal face of the substrate is {n11} crystal face family, n is 0 or an integer greater than 1, and anisotropic gain can be obtained in the VCSEL by using the non-(001)-oriented substrate and the quantum well, so that polarization in a quantum well plane (active region) is controlled to obtain higher gain, a grating structure does not need to be additionally arranged, the preparation process is simplified, and the preparation cost is reduced.

The invention relates to the technical field of chip preparation, and provides a chip based on an annular photonic crystal and a preparation method thereof. The preparation method comprises the following steps: growing a nucleating layer on a substrate; growing a superlattice structure on one side, away from the substrate, of the nucleating layer; sequentially growing an n-type coating layer, an n-type waveguide layer, a quantum well and a p-type electron blocking layer on one side, deviating from the nucleating layer, of the superlattice structure; etching a plurality of annular cavities on the p-type electron barrier layer to form an annular photonic crystal; growing a p-type extension contact layer on one side, deviating from the quantum well, of the p-type electron blocking layer; and carrying out in-situ annealing treatment. According to the preparation method, the directivity of the photonic band gap can be effectively adjusted, uniform light waves in all directions on the side face can be formed, so that leakage of laser from a non-light-emitting area on the side face is restrained, the light emitting efficiency is improved, the annular photonic crystals are periodically distributed, and the light beam quality is effectively guaranteed.

The invention provides an EML laser and a preparation method of an air bridge, belongs to the technical field of optical communication lasers, and is used for solving the problem that the stray capacitance of connecting metal between a waveguide electrode and a PAD electrode of the EML laser is too large. The preparation method of the air bridge process of the EML comprises the following steps: growing a mask layer on the surface of an epitaxial InP wafer, photoetching to form a ridge waveguide pattern, etching the mask layer by adopting ICP (Inductively Coupled Plasma), and removing photoresist; etching the ohmic contact layer by adopting ICP (Inductively Coupled Plasma) and removing the mask layer; gluing and photoetching the surface of the wafer to form a pier pattern; adopting ICPCVD to grow a dielectric film at low temperature; gluing and photoetching the surface of the wafer to form a dielectric film bridge pattern; carrying out ICP etching on the dielectric film and removing the bridge and pier photoresist to form a dielectric film bridge; and performing wet etching on the InP epitaxial layer to the etching stop layer. According to the method, the dielectric film bridge is built at the connecting metal between the waveguide electrode and the PAD electrode, the low dielectric constant characteristic of air is utilized, the distance between the metal and the quantum well is greatly increased, the stray capacitance of the EML is reduced, and the bandwidth is improved.

The invention relates to the technical field of LEDs, in particular to a quaternary yellow-green LED epitaxial wafer and a preparation method thereof. The quaternary yellow-green LED epitaxial wafer sequentially comprises a GaAs substrate, a GaAs buffer layer, an N-type gradient doped waveguide layer, a single quantum well active layer, a P-type gradient doped waveguide layer, a P-type self-absorption layer, a P-type transition layer and a P-type periodic current expansion layer from bottom to top. Through the design that the N / P type gradient doped waveguide layer is combined with the single quantum well active layer, the P type self-absorption layer and the P type GaP / GaAsP periodic current expansion layer, and the MOCVD technology is adopted for growth, the obtained low-brightness and high-reliability quaternary yellow-green LED epitaxial wafer structure has the advantages of being high in antistatic performance, excellent in aging performance, good in surface flatness and uniformity, high in light emitting efficiency and the like. The method has the characteristics of simple process, low production cost and raw material cost and the like, is used for replacing two-component and three-component LEDs grown by an LPE technology, and has better reliability and application prospect.

The invention provides a display chip, a display device and a preparation method thereof, and the display chip comprises an epitaxial layer which comprises a first semiconductor layer, a quantum well light-emitting layer and a second semiconductor layer, the first reflecting layer is positioned on one side, deviating from the first semiconductor layer, of the second semiconductor layer; the first metal binding layer is located on the side, away from the epitaxial structure, of the first reflecting layer; the heat dissipation layer comprises a first heat dissipation layer and / or a second heat dissipation layer, the first heat dissipation layer is located between the epitaxial structure and the first reflection layer, the second heat dissipation layer is located on the side, away from the epitaxial structure, of the first reflection layer, and the second heat dissipation layer is provided with a first opening exposing the first reflection layer; the first metal binding layer is arranged on the side, away from the first reflecting layer, of the second heat dissipation layer and fills the first opening. The heat dissipation performance of the display chip can be improved.

According to the deep ultraviolet LED device provided by the invention, a first stress regulation and control layer and a second stress regulation and control layer are sequentially arranged between an electron injection layer and a quantum well active layer, and the Al component content x2 of the first stress regulation and control layer and the Al component content x3 of the second stress regulation and control layer meet the following relations: x3 < = (x4 + x5) / 2, x2 > = (x1 + x3) / 2, x4 > x3 > x5; according to the invention, by regulating and controlling the Al component content of each layer, the lattice mismatch between the second stress regulation and control layer and the quantum well active layer is reduced, and the lattice mismatch among the electron injection layer, the first stress regulation and control layer and the second stress regulation and control layer is reduced, so that the tensile stress can be applied to the quantum well active layer, and the performance of the device is improved. Therefore, the pressure stress generated by the bottom epitaxial structure on the quantum well active layer is compensated, and the light-emitting efficiency of the deep ultraviolet LED device is finally improved.

The invention provides a semiconductor laser chip with a current modulation function and a preparation method, and relates to the field of semiconductor laser chips, and the semiconductor laser chip comprises a substrate layer, an n-type limiting layer, an n-type waveguide layer, a quantum well active region, a p-type waveguide layer, a first p-type limiting layer, a second p-type limiting layer and a contact layer which are sequentially stacked from bottom to top, the anti-reflection cavity surface and the high-reflection cavity surface are arranged on the two opposite sides of the second p-type limiting layer, the functional area is arranged between the anti-reflection cavity surface and the high-reflection cavity surface and comprises a current injection sub-area and a current blocking sub-area, the current injection sub-area is provided with a plurality of injection tips, the current blocking sub-area is provided with a plurality of blocking tips, and the injection tips and the blocking tips are arranged on the first p-type limiting layer. The injection tip is arranged between any two adjacent blocking tips; two grooves formed in the first p-type limiting layer penetrate through the second p-type limiting layer and the contact layer, and the two grooves are located in the two opposite sides of the current injection sub-region and the current blocking sub-region. According to the semiconductor laser chip, the light emitting power and the light beam quality of the semiconductor laser chip can be improved.

The invention discloses a deep ultraviolet LED epitaxial structure, a deep ultraviolet LED device comprising the same and a preparation method, and the epitaxial structure sequentially comprises a sapphire substrate, an AlN nanowire array layer, an AlN intrinsic layer and an AlGaN light-emitting structure layer from bottom to top. The AlGaN light-emitting structure layer further comprises an n-type AlGaN electron injection layer, a quantum well active layer, a p-type AlGaN electron blocking layer and other device structures. According to the invention, the vertically arranged AlN nanowire array is introduced to replace a traditional AlN buffer layer, so that lattice mismatching stress caused by a substrate is significantly released, and the dislocation density of an epitaxial layer is effectively reduced; meanwhile, the introduction of the AlN intrinsic layer further flattens the epitaxial interface and optimizes the lattice quality, thereby providing a high-quality template for the growth of a high-performance AlGaN material. The epitaxial structure is suitable for an LED device in a deep ultraviolet band, and the crystal quality, the electrical property and the luminous efficiency of the device can be improved.

The invention discloses a thermal-decay-resistant red light Micro LED epitaxial structure and a preparation method thereof. The epitaxial structure sequentially comprises a substrate layer, an n-type buffer layer, an n-type etching barrier layer, an n-type ohmic contact layer, an n-type limiting layer, a quantum well structure, a p-type spacer layer, a p-type electron barrier layer and a p-type ohmic contact layer from bottom to top. Wherein the quantum well structure is formed by alternating 1-5 pairs of InGaP well layers and three-section type p-type AlGaInP barrier layers, and the three sections of barrier layers adopt gradient energy level design and are all subjected to p-type doping; according to the invention, the problems of carrier loss and low recombination efficiency at high temperature in the prior art are solved by blocking electron overflow through the gradient energy level barrier and supplementing the hole concentration through p-type doping, so that the 85 DEG C external quantum efficiency attenuation rate is less than or equal to 10%, the service life is prolonged to more than 50,000 hours, and the process is compatible with mass production and is suitable for the fields of display, illumination and the like.

The invention provides a heterojunction quantum well and a preparation method thereof, and the method comprises the steps: providing a substrate, and forming a heterojunction quantum well at one side of the substrate through a chemical vapor deposition method; the heterojunction quantum well comprises a first barrier layer, a quantum well layer and a second barrier layer which are stacked in sequence, the first barrier layer is located between the quantum well layer and the substrate, the first barrier layer and the second barrier layer are both made of germanium-silicon, when the heterojunction quantum well is a silicon heterojunction quantum well, the quantum well layer is a silicon quantum well layer, and when the heterojunction quantum well is a silicon quantum well layer, the second barrier layer is a silicon quantum well layer. When the heterojunction quantum well is a germanium heterojunction quantum well, the quantum well layer is a germanium quantum well layer; in the process of forming the heterojunction quantum well, the precursor is decomposed in a target temperature range, and a product obtained through decomposition is deposited on one side of the substrate to obtain the heterojunction quantum well; the precursor is subjected to multi-stage reaction during decomposition, and the target temperature range is 300-550 DEG C; the interface quality of the heterojunction quantum well can be greatly improved, the surface roughness of the film layer can be reduced, and high-quality preparation of the heterojunction quantum well is realized.

The invention relates to the technical field of semiconductor photoelectrons, and discloses a vertical-cavity surface-emitting laser with an inverted structure and a preparation method of the vertical-cavity surface-emitting laser. The vertical cavity surface emitting laser with the inverted structure comprises a heterogeneous substrate, wherein a heat dissipation functional layer, a metal adhesion layer and a metal bonding layer are arranged on the surface of the heterogeneous substrate from bottom to top; the epitaxial structure comprises a p-type electrode, an ITO current expansion layer, a SiO2 current limiting layer, a first dielectric DBR layer, a p-type GaN layer, an electron blocking layer, a quantum well active region, an n-type GaN layer, a second dielectric DBR layer and an n-type electrode from bottom to top; and the p-type electrode is positioned at the bottom of the epitaxial structure and is bonded with the metal bonding layer to form an inverted structure. According to the vertical cavity surface emitting laser with the inverted structure provided by the invention, the heat dissipation function layer and the inverted structure design effectively improve the heat dissipation capability and the current uniformity of the device, and the service life, the performance stability and the reliability of the device are remarkably improved.

The invention relates to the technical field of semiconductor light-emitting devices, and particularly discloses an epitaxial structure for improving the internal quantum efficiency of a green Micro LED. The epitaxial structure comprises a substrate, and a buffer layer, an undoped GaN layer, an n-type GaN layer, a stress release layer, an active layer, a low-temperature Mg heavily-doped GaN layer, an electron barrier layer, a p-type GaN layer and a p-type GaN contact layer which are sequentially arranged on the substrate. The active layer comprises a plurality of periods of InGaN quantum well layers and an InAlGaN / GaN superlattice quantum barrier layer alternating structure, and a CAP layer formed by an AlGaN / GaN superlattice is arranged behind each quantum well layer. By adopting a wide-well narrow-barrier structure, a superlattice CAP layer for neutralizing a polarization electric field and a quaternary InAlGaN barrier structure for lattice matching and hole injection enhancement, multiple regulation and control of a polarization field, dislocation density and hole transport are realized, the internal quantum efficiency of a green-light Micro LED is remarkably improved, and the green-light Micro LED epitaxial structure is suitable for epitaxial preparation of a high-performance Micro LED chip.

The utility model provides a laser, a hybrid integrated optical chip and an optical module. The laser comprises a P-InP ohmic contact layer, a P-type InP layer, a quantum well layer, an N-InP ohmic contact layer, an N-type InP layer and a waveguide layer from top to bottom. Wherein the P-type InP layer provides P-type carriers for the quantum well layer, and the N-type InP layer provides N-type carriers for the quantum well layer. And the P-type carriers and the N-type carriers are compounded in the quantum well layer to generate light. The waveguide layer is located below the quantum well. The optical confinement factor of the waveguide layer is larger than the optical confinement factor of the quantum well layer, so that the light field in the quantum well layer is large, the light is downwards coupled into the waveguide layer, and then light is output through the waveguide layer. The laser provided by the embodiment of the utility model emits light downwards and then outputs the light horizontally. The laser provided by the embodiment of the utility model can be integrated in a silicon optical chip, so that light emitting and modulation are integrated in the same chip.

The invention discloses a graphene integrated electrode LED epitaxial structure and a chip preparation method. The epitaxial structure sequentially comprises a GaAs substrate, an n-type GaAs buffer layer, an n-type limiting layer, a non-doped quantum well structure, a p-type spacer layer, a p-type electron barrier layer and a p-type GaP ohmic contact layer from bottom to top. The preparation method comprises the steps of epitaxial structure growth, p-type ITO transparent conductive layer preparation, bonding and substrate removal, mesa structure preparation, passivation isolation, graphene interconnection layer preparation and n-type electrode preparation. Graphene is used for replacing a traditional n-type GaAs ohmic contact layer and an ITO electrode, the problems of poor red light absorption, poor heat dissipation and mechanical brittleness of a traditional structure are solved, the red light transmittance of the chip is improved, the junction temperature under 3 currents is greatly reduced, the chip can bear tensile strain larger than 20%, the chip is suitable for flexible scenes, and the chip is suitable for high-performance large-scale production of red light Micro LEDs.

In order to provide an IR-QCL element which utilizes the characteristics of a ZnO-based semiconductor material, the present disclosure discloses a quantum cascade laser element 1000 that has a plurality of unit structures 10U in each of which a well layer of ZnO or ZnMgO and a barrier layer of ZnMgO or MgO are alternately and repeatedly stacked. Each unit structure includes a light emitting layer 10E and a continuum layer 10C. The light emitting layer includes: an upstream well layer 10W1 that is composed of a step quantum well having a first layer and a second layer, which have different MgO composition ratios from each other; and a downstream well layer 10W2 that has a smaller MgO composition ratio than any of the first layer and the second layer.

A monitoring device system has a tunable VCSEL laser having one or more active regions including quantum wells and barriers. The active regions are surrounded by one or more p-n junctions. The one or more active regions can include a selected shape structure, as well as one or more tunnel junctions (TJ). One or more apertures are provided with the selected shape structure. One or more buried tunnel junctions (BTJ) or oxide confine the apertures, additional TJ's, planar structures and or additional BTJ's created during a regrowth process that is independent of a first growth process. A VCSEL output is determined in response to an application of the VCSEL laser. The VCSEL laser includes an HCG grating and a bottom DBR. A receiver receives the optical radiation that is reflected from a target scene and is indicative of respective times of flight of the pulses to and from a target scene. A processor and control circuit select a first pulse repetition interval (PRI), a second PRI, greater than the first PRI, and a third PRI, greater than the second PRI, from a permitted range of PRIs, and to drive the VCSEL laser to emit a first sequence of the pulses at the first PRI as well as a second sequence of the pulses at the second PRI, and a third sequence of the pulses at the third PRI, and to process the signals output by the receiver in response to the first, second, and third sequences of the pulses in order to compute respective depth coordinates of the points in the target scene.

A flip-chip bonded photonic device and methods of fabrication are described. The device has a spot size converter and an antireflective coating on a sidewall of the spot size converter. The device has a semiconductor layer comprising a stack of quantum wells and an etch stop semiconductor layer beneath the layer comprising a stack of quantum wells. The device has a vertical sidewall for optical coupling and a sloped sidewall for metal interconnects. The device has a substrate and an optical waveguide residing above substrate. A mirror is coupled to the optical waveguide that bends light from the optical waveguide and transmits the light through the substrate. The light expands as it passes through the substrate. A collimating lens receives the light transmitted through the substrate and is lithographically aligned with the mirror. An optical engine has a flip-chip integrated electro-absorption modulated laser (EML) on a substrate.

Provided are optical transformer devices having a high power efficiency. The device architecture provides uniform current spreading to minimize efficiency droop. The quantum well designs are optimized for both light-emitting diode (LED) and photo diode (PD) operation. A low-loss optical cavity allows efficient transfer of light from the LED junction to the PD junction. The architecture provides a low-loss voltage up- and down-conversion and provides compatibility with production-grade epitaxial growth and wafer fabrication processes.

The invention belongs to the technical field of optical communication, and particularly relates to a narrow linewidth laser based on a cascaded micro-ring resonant cavity. The laser comprises a semiconductor laser inner cavity module, a gain chip module, a phase shifter, a cascade micro-ring resonant cavity module, a thermal tuning module and an outer cavity reflector. The gain chip is combined with an III-V group material at the top of the silicon waveguide through heterogeneous integration, and adopts an InAlGaAs quantum well to provide high gain; the phase shifter is used for matching the lasing wavelength with the resonant wavelength; the cascaded micro-ring resonant cavity is formed by cascading three micro-rings, and tuning of the laser is realized based on a vernier effect; the thermal tuning module is composed of three semi-annular metal strips and a straight waveguide-shaped metal strip. The outer cavity reflector module adopts a Sagnac ring structure; the laser inner cavity, the gain chip, the cascade micro-ring resonant cavity and the outer cavity reflector are directly connected through silicon waveguides. The laser has the characteristics of narrow linewidth and wide tuning range, is easy to highly integrate and interconnect, and has important application value.

The invention discloses a semiconductor laser and a preparation method thereof, which can be used in the field of semiconductor device preparation, and the method comprises the steps: firstly, providing a first conductive type substrate; then, epitaxially growing a buffer layer of a first conduction type, a lower optical waveguide limiting layer, a quantum well active light-emitting layer, an upper optical waveguide limiting layer, a corrosion barrier layer, a current injection layer and an intrinsic ohmic contact layer on the substrate in sequence to obtain a multi-layer epitaxial layer; then, etching the multi-layer epitaxial layer to the corrosion barrier layer based on a preset pattern to form a ridge-shaped table which starts from the intrinsic ohmic contact layer and is deeply cut off to the corrosion barrier layer; and finally, performing particle doping in a region corresponding to the ridge-shaped table, and converting one sides, close to the corrosion barrier layer, of the intrinsic ohmic contact layer, the current injection layer, the corrosion barrier layer and the upper optical waveguide limiting layer into a second conduction type. Therefore, current limitation can be realized without performing multiple epitaxy like a traditional buried heterojunction, and the production cost and the process difficulty are greatly reduced.

The invention discloses an AlGaInP red light LED chip structure with a polarization-induced tunnel junction and a preparation method thereof. The chip structure sequentially comprises a GaAs substrate, an n-type GaAs buffer layer, an n-type etching barrier layer, an n-type GaAs ohmic contact layer, an n-type limiting layer, a non-doped InGaP / quantum well structure, a p-type spacer layer, a p-type AlGaInP polarization-induced doping layer, an insertion layer and an n-type ohmic contact layer from bottom to top. Wherein the p-type AlGaInP polarization induction doping layer introduces a piezoelectric polarization electric field through an Al component gradual change design, high-density two-dimensional hole gas is formed through induction, and the high-Al component insertion layer and the n-type ohmic contact layer form a tunnel junction; according to the invention, the problems of low p-type doping efficiency and high resistivity of the AlGaInP material with high Al component are fundamentally solved, the epitaxial structure and the chip process are simplified, the series resistance of the chip is reduced, the luminous efficiency is improved, the yield is improved, and the method has remarkable technical and commercial values.