Research On Linewidth Characteristics Of Negative Feedback Semiconductor Laser Based On Microring Resonator

The semiconductor laser is a kind of laser that uses the semiconductor material as gain medium to achieve optical amplification,thereby generating a laser output.Compared with other types of lasers,the semiconductor laser possesses obvious advantages:small size,high luminous efficiency,good operability of direct modulation,and good integration capability.Based on the above advantages,semiconductor lasers have been widely used in coherent optical communications,optical fiber sensing,coherent detection and other fields.However,with the rapid advancement of science and technology,people have raised higher expectations for the development of these fields.As the main applied light source in these fields,it is more and more difficult to meet the needs of development with their poor spectral performance.Therefore,in all fields,there has been an upsurge of research on narrow-line-width semiconductor lasers.Among currently reported research projects,the external cavity semiconductor laser scheme has been optimized by designing the external structure of the laser cavity.The structure is simple and easy to implement,and it also has good spectral performance.So it has been a significant research direction for researchers.The scheme is based on an excellent frequency-selective component-micro-ring resonator as the external cavity structure,which provides feedback light for the main laser cavity to achieve the lasing mode control and achieve the purpose of narrowing the line-width.The laser system adopts a coherent optical negative feedback mechanism.Compared with other existing schemes,it avoids the output light from passing through the external cavity structure and bringing about excessively high energy loss.At the same time,the usage of the micro ring resonator with fine frequency selectivity characteristic can provide effective feedback light.So the dual guarantee of line width and output power performance can be achieved at the same time.This article systematically analyzes the external cavity semiconductor laser scheme.Firstly,according to the requirements of the laser system,the structures of each component were designed to achieve the corresponding performance requirements;then the operating mechanism of the system was carefully analyzed in detail,and the feasibility of the scheme was demonstrated under ideal conditions;finally,the field The external cavity semiconductor laser system was built to verify the practical application value of the scheme.Test results show that this scheme has a low pumping threshold,and yet the output power can reach about 7.85 mW.Meanwhile,the side-mode suppression ratio of the output spectrum can reach about 62 dB,with a final laser line-width measurement value of 5.5 KHz.The excellent performance of oiur scheme makes it in a better level in the current domestic and international reports.Based on the above discussion,taking into account that the program has the advantages of simple structure and low cost,and combining its excellent line-width performance,this paper has certain reference value for the realization of the industrialization of high performance narrow line-width semiconductor lasers in the future.