Study On Phase Shift Grating Characterustics Of Distributed Deedback Semiconductor Lasers

This thesis is based on the National High-Tech Development Project “High Linearity Laser and High Saturated Power Photodetector Array Chip”(Project No.2015AA016901).To develop a 1310 nm four-channel semiconductor laser for long-distance optical communication,use ALDS simulation software.The grating type,etching position,distribution coupling coefficient and multi-phase shift of the distributed feedback semiconductor laser diode(DFB LD)are analyzed and optimized.In cooperation with Wuhan Guangxun and the Institute of Semiconductors of the Chinese Academy of Sciences,the laser chips were designed and produced.This thesis mainly includes the following aspects of research:1?Comparing the AlGaInAs/InP material system with the InGaAsP/InP material system,the AlGaInAs/InP material system was used to prepare DFB LD.2 ? Based on ALDS simulation experiments,through the analysis and comparison of the simulation results,it is found that to improve the light field aggregation of the laser and optimize the spatial hole burning effect,the refractive index coupling type asymmetric phase shift grating is determined,and the grating is increased.On the upper layer of the active layer.In the actual preparation process,the low-damage ICP dry etching method and E-beam exposure method are used to accurately etch the duty ratio and height of the grating,which helps to optimize the spatial hole burning effect and improve the relaxation oscillation frequency.It helps the chip to be modulated at high speed.3?The epitaxial growth of the chip is carried out by MOCVD method,and the growth conditions are changed according to actual needs,the growth scheme is determined,and A high-quality epitaxial wafer is obtained,thereby preparing for 1310 nm four-channel DFB LD capable of achieving high linearity and high power direct modulation.4?With the LD structure design and laser material simulation software ALDS,the material system of the laser chip is compared,the device structure is designed and analyzed,and the performance of the chip is optimized,and the technical parameters such as threshold current,wavelength and SMSR are obtained.Subsequent analysis processes provide the basis.Finally,laser chip with 1310 nm(high frequency response covering the frequency range below 12 GHz)and single channel chip with an output power greater than 10 dBm was successfully developed.Moreover,the sample chip test results show that the technical indicators of the developed laser chip have reached the project requirements,and most of them are better than the project requirements.