Study On Key Technology Of Surface Emitting Distributed Feedback Semiconductor Lasers

Surface emitting distributed feedback semiconductor lasers is a kind of semiconductor lasers of high power,high beam quality,narrow line width,low temperature drift,which using the F-P cavity for laser gain oscillation and emitting light vertically by second-order grating first-order diffraction.It has broad application prospects in laser radar,laser detection,information processing,laser industrial processing and many other fields because of its advantages——simple preparation process,excellent and stable working performance and so on.The key technologies involved in the design and fabrication process of surface emitting distributed feedback semiconductor laser is studied in this paper.1.The present situation and status of research and development at home and abroad are investigated and the preliminary analysis and discussion about it are made.2.The design and fabrication of the light window is of vital important for the whole device,Two feasible schemes about the light window are proposed,the structure of schemes have been designed,optimized and analyzed.Two feasible schemes(single layer HfO2 film and subwavelength anti-reflective grating)can meet the device requirements(transmissivity > 99.4%).3.The second order grating,key structure of distributed feedback laser for exiting light vertically,has been calculated initially and produced,the grating with the period of 300 nm and 450 nm,ridge height of 200 nm and 185 nm and corresponding complete preparation process are obtained.4.The influence of each element of external cavity(resonator output end,beam splitter and grating)on the threshold gain of composite external cavity semiconductor laser is analyzed.Combined with the whole analysis of the composite external cavity,the possibility of further optimization of the composite external cavity laser is explored.