Study On Injection-locked Semiconductor Laser Based On Reconstruction-equivalent-Chirp Technique

Since information-era comes,the conventional communication technology with electronic and electric carriers is increasingly unable to meet the needs of society development.The invention and development of optical fiber communication technology has led great changes in communication technology.Semiconductor lasers,which are the light source of optical fiber communication system,have also come a long way.However,as the communication system develops in the direction of higher transmission speed,larger information capacity and longer distance transmission,the requirements of the properties of the semiconductor laser,such as modulation bandwidth,nonlinear distortion,transmission performance and linewidth,are also growing.It has been proved that optical injection-locking technique can effectively improve the modulation property and linewidth of the laser,In this paper,the injection-locked semiconductor laser is introduced,and the influence of the injection-locking method on of the modulation property and linewidth of the laser is studied.The main contents are as follows:In the first chapter,the development of semiconductor laser is introduced briefly,and at the same time,the development status and realization method of injection-locked semiconductor laser are introduced.In the second chapter,we will introduce the reconstruction-equivalent-chirp(REC)technique in details,including its working principle and the fabrication process of the complex grating structure based on REC technique.The complex equivalent sampling Bragg grating structures based on REC technique can be realized by using conventional holographic exposure and ordinary secondary lithography process,which makes REC technique cheaper and more accurate compared to the traditional electronic beam lithography.In the third chapter,a monolithic optical injection-locked semiconductor laser is proposed,and the influence of the injection-locking method on the modulation properties of the laser is experimentally demonstrated.Compared to the free-running state,the relaxation oscillation frequency is improved about 20 GHz in the injection-locked state.The nonlinear distortions,including the 1-dB compression point,second harmonic distortion(2HD)and third-order intermodulation distortion(IMD3),are also suppressed significantly.In the 50 km transmission experiment,the error vector magnitude(EVM)of the whole link is reduced from 5.25%to 2.94%using injection locked technique.In the fourth chapter,a parallel hybrid integrated injection-locked semiconductor laser is proposed.The influence of the injection-locking method on the linewidth of the laser is experimentally demonstrated.The linewidth of the laser is narrowed from 1034.2 kHz to less than 100 kHz through optical injection-locked technique.The fifth chapter is the summary and prospect of this paper.