CN-121983847-A - Polarization state-adjustable integrated laser chip

CN121983847ACN 121983847 ACN121983847 ACN 121983847ACN-121983847-A

Abstract

The invention discloses an integrated laser chip with a controllable polarization state, which comprises a substrate, a lower waveguide layer, a superlattice quantum cascade active layer and a passive layer, wherein the lower waveguide layer is arranged on the substrate, the superlattice quantum cascade active layer and the passive layer are arranged on the lower waveguide layer side by side, a first upper waveguide layer is arranged on the superlattice quantum cascade active layer, a distributed feedback grating is arranged in the first upper waveguide layer, a second upper waveguide layer is arranged on the passive layer, a photonic crystal is arranged on one side, away from the first upper waveguide layer, of the second upper waveguide layer, a contact layer and a laser electrode are laminated on the first upper waveguide layer, and a splitting ratio control heating electrode, a first phase control heating electrode and a second phase control heating electrode are arranged on the second upper waveguide layer. The laser chip can realize the regulation and control of the output polarization state without external components, and has the advantages of small volume and high light source integration level.

Inventors

GUO KAI
ZHAO JIANZHONG
Gu Tongshun
YANG YONG
JIA ZHIWEI

Assignees

苏州芯晟半导体科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251229

Claims (10)

1. An integrated laser chip with adjustable polarization state, comprising: A substrate; A lower waveguide layer disposed on the substrate; the superlattice quantum cascade active layer and the passive layer are arranged on the lower waveguide layer side by side; a first upper waveguide layer is arranged on the superlattice quantum cascade active layer, a distributed feedback grating is arranged in the first upper waveguide layer, a second upper waveguide layer is arranged on the passive layer, and a photonic crystal is arranged on one side, away from the first upper waveguide layer, of the second upper waveguide layer; And the first upper waveguide layer is provided with a contact layer and a laser electrode in a laminated manner, and the second upper waveguide layer is provided with a splitting ratio regulating heating electrode, a first phase regulating heating electrode and a second phase regulating heating electrode.
2. The integrated laser chip of claim 1, wherein the integrated laser chip comprises a distributed feedback quantum cascade laser region, a directional coupler region, a phase modulation region, and a photonic crystal coupled emission region integrated on the substrate; The superlattice quantum cascade active layer, the first upper waveguide layer, the contact layer and the laser electrode are located in the distributed feedback quantum cascade laser region; the splitting ratio regulating heating electrode is positioned in the directional coupler region; the first phase regulation heating electrode and the second phase regulation heating electrode are positioned in the phase regulation region; The photonic crystal is positioned in the photonic crystal coupling emission region.
3. The integrated laser chip of claim 2, wherein the distributed feedback quantum cascade laser region is configured to emit laser light under direct current drive, the laser light is transmitted to the directional coupler region, the heating electrode is split into two paths of light by the splitting ratio regulation, the two paths of light are transmitted through the phase regulation region, enter the photonic crystal coupling emission region from different directions, are coupled into the same mode in the photonic crystal, and a part of light is emitted out of the laser chip perpendicular to the plane of the photonic crystal; When the two paths of optical coupling phases are the same or differ by 180 degrees, the output laser is linearly polarized light, when the two paths of optical coupling phases differ by 90 degrees, the output laser is left circularly polarized light, and when the two paths of optical coupling phases differ by 270 degrees, the output laser is right circularly polarized light.
4. The integrated laser chip of claim 3, wherein the control of the split ratio of the two paths of light is achieved by changing the voltage of the split ratio control heating electrode and changing the coupling phase of the two paths of light.
5. The integrated laser chip of claim 3, wherein the phase difference of the two light paths is controlled by changing the voltages of the first phase adjusting heating electrode and the second phase adjusting heating electrode.
6. A polarization-tunable integrated laser chip according to claim 3, wherein two paths of light enter the photonic crystal at an angle perpendicular to each other, and the photonic crystal is a (2, 0) level tetragonal photonic crystal, and is precisely matched with the wavelength of the laser light emitted by the distributed feedback quantum cascade laser region.
7. The tunable integrated laser chip of claim 6, wherein the second upper waveguide layer comprises a first tapered waveguide and a second tapered waveguide, wherein the output planes of the first tapered waveguide and the second tapered waveguide are larger than the input plane, wherein the output plane of the first tapered waveguide is aligned with the first face of the square photonic crystal, wherein the output plane of the second tapered waveguide is aligned with the second face of the square photonic crystal, and wherein the first face and the second face are perpendicular to each other.
8. The integrated laser chip of claim 1, wherein the superlattice quantum cascade active layer is a binaural resonance active region comprising 30 periods, and the period of the distributed feedback grating is 719 nm, forming a distributed feedback resonant cavity.
9. The integrated laser chip of claim 1, wherein the split ratio control heating electrode, the first phase control heating electrode, and the second phase control heating electrode are all nichrome.
10. The integrated laser chip of claim 2, wherein the distributed feedback quantum cascade laser region, the directional coupler region, the phase modulation region, and the photonic crystal coupled emission region are sequentially arranged on the substrate.

Description

Polarization state-adjustable integrated laser chip Technical Field The invention relates to the technical field of semiconductor lasers and photon integration, in particular to an integrated laser chip with adjustable polarization state. Background Semiconductor lasers have the advantages of small size, high efficiency, long service life, low cost and the like, and become one of the most widely used laser types at present, and the semiconductor lasers are applied to cover a plurality of fields of optical communication, optical sensing, optical storage, scientific research, industry, medical treatment, consumer electronics and the like. By regulating the polarization characteristics of the semiconductor laser, the optical communication capacity and the optical sensing precision can be improved, and many demands are also made in the scientific research and medical fields. For example, polarized light can be used for representing tissue structure characteristics in biomedical research and clinical application, and can be used for chiral characteristic identification in molecular spectroscopy and sensing application, and the circularly polarized light has important application value in the aspects of special optical operation and 3D imaging. The common laser polarization state regulation and control needs to be combined and controlled through external vertical elements such as an external wave plate, a polarization controller, a phase plate, a spatial light modulator and the like, so that the system is large in volume, low in regulation and control efficiency and unfavorable for system integration. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide an integrated laser chip with adjustable polarization state, which realizes coherent synthesis of different polarized lights based on a two-dimensional photonic crystal, thereby realizing output and adjustment of linear polarized lights with different polarization directions, circular polarized lights with different rotation directions and elliptical polarized lights. The invention provides an integrated laser chip with a controllable polarization state, which comprises a substrate, a lower waveguide layer arranged on the substrate, a superlattice quantum cascade active layer and a passive layer which are arranged on the lower waveguide layer side by side, wherein a first upper waveguide layer is arranged on the superlattice quantum cascade active layer, a distributed feedback grating is arranged in the first upper waveguide layer, a second upper waveguide layer is arranged on the passive layer, a photonic crystal is arranged on one side, away from the first upper waveguide layer, in the second upper waveguide layer, a contact layer and a laser electrode are laminated on the first upper waveguide layer, and a splitting ratio control heating electrode, a first phase control heating electrode and a second phase control heating electrode are arranged on the second upper waveguide layer. The integrated laser chip comprises a distributed feedback quantum cascade laser region, a directional coupler region, a phase regulation region and a photonic crystal coupling emission region which are integrated on the substrate, wherein the superlattice quantum cascade active layer, the first upper waveguide layer, the contact layer and the laser electrode are located in the distributed feedback quantum cascade laser region, the splitting ratio regulation heating electrode is located in the directional coupler region, the first phase regulation heating electrode and the second phase regulation heating electrode are located in the phase regulation region, and the photonic crystal is located in the photonic crystal coupling emission region. Optionally, the distributed feedback quantum cascade laser region is used for emitting laser under direct current drive, the laser is transmitted to the directional coupler region, the heating electrode is regulated and controlled by the splitting ratio to be divided into two paths of light, the two paths of light are transmitted through the phase regulating region and enter the photonic crystal coupling emission region respectively from different directions, the two paths of light are coupled into the same mode in the photonic crystal, and meanwhile, a part of light is emitted out of the laser chip perpendicular to the plane of the photonic crystal, when the two paths of light coupling phases are the same or 180 DEG different, the output laser is linearly polarized light, when the two paths of light coupling phases are 90 DEG different, the output laser is left-handed circularly polarized light, and when the two paths of light coupling phases are 270 DEG different, the output laser is right-handed circularly polarized light. Optionally, the voltage of the heating electrode is regulated and controlled by changing the splitting ratio, and the coupling phase of the two paths of light is changed, so that the r