Design And Study Of Active Semiconductor Devices For Photonic Integrated Applications

Optical communication technology is the technological cornerstone of modern information society.With the development of artificial intelligence technology and the advent of the era of big data,the demand for information exchange with high speed,large capacity and low latency is increasing day by day.Optical fiber communication technology based on photonic integration technology has great potential in improving the existing information exchange speed and communication capacity,and has been gradually applied in high-speed data centers and other core optical fiber communication systems.Optical fiber signal transceiver based on photonic integration is the core device of optical fiber communication.However,its fabrication has some problems,such as complex manufacturing process,high cost of chip manufacturing,which is not conducive to large-scale production.Multimode interferometric waveguide structure is a common passive device in photonic integration.Its structure is simple and compact,which is very convenient for processing.It has been widely used in power divider,wavelength division multiplexing,optical switch,optical coupler and other fields.In this paper,by improving the existing III-V laser chip structure and introducing active multi-mode interference waveguide structure as beam splitter,coupler and amplifier,an optical transceiver structure which can be fabricated on III-V substrate without secondary epitaxy is proposed,which simplifies the existing process scheme of photonic integrated optical transceiver.In this paper,we mainly study the photonic integration technology based on III-V multi-quantum well active substrates without secondary growth.By integrating980 nm band single-mode DFB semiconductor lasers on active substrates and on-chip optical amplifiers at the back end,the laser beam quality is optimized,the catastrophic effect of the cavity surface is suppressed and the output power of the laser is improved.(1)Analyzing and simulating the structure of multi-mode interference waveguideby various simulation methods.By analyzing the working mode of active multi-mode interference waveguide(Active MMI),an improved finite-time-domain difference(FDTD)algorithm is proposed.This algorithm can track and simulate the dynamic characteristics of light field distribution in Active MMI devices.Compared with the traditional similar algorithm,the approximate algorithm is eliminated.It consumes very little computing resources,which is conducive to large-scale and high-precision simulation calculation.(2)A semiconductor laser chip with multi-mode interference waveguide as laser resonator is designed and fabricated;a laser chip structure with DFB laser and active MMI as laser resonator is proposed,which is modeled and simulated;the transverse optical field distribution is calculated by Lastip software,and the carrier distribution in the device is calculated by PICS3 D software.The device is simulated by the self-developed FDTD algorithm,and the corresponding device is fabricated.Compared with ridge semiconductor lasers of the same length and size,the output power and electro-optical conversion efficiency of the laser are improved to a certain extent.(3)A novel thermo-optic modulation structure based on polymer planar optical path hybrid integrated platform is proposed.By introducing graphene as micro-heating wire,this structure effectively reduces the power consumption of the traditional thermo-optic modulation structure and improves the response speed of the traditional thermo-optic modulation structure.While comparing the performance of traditional devices with simulation,the specific manufacturing process is proposed.The compatibility of the structure with general power supply and the tolerance range of the design are analyzed and verified.