Structure Optimization And Verification Of 976nm Laser

The pump light energy provided by 976nm high-power semiconductor laser matches the absorption peak of ytterbium doped fiber laser,which has been widely used in the field of fiber laser pumping.Engineering research on laser chip has become one of the laser research hotspots in recent years.In this paper,the 976nm quantum well laser is taken as the research object,and the research is carried out from four aspects of structure analysis,simulation,experimental testing and equivalent circuit modeling.The main work contents and research achievements include:Firstly,the effects of active region composition and thickness,waveguide layer structure,cavity length and non-injected window on the laser characteristics are theoretically analyzed.To improve the output power,an asymmetric waveguide layer and a limiting layer structure are introduced to determine the material structure of a 976 nm Asymmetric Decoupled Confinement Heterostructure(Asymmetric Decoupled Confinement Heterostructure,ADCH)semiconductor laser.Based on the mechanism of thermal damage caused by carrier injection to the active cavity surface,the influence of current non-injection window on the temperature,light field and carrier variation of the active cavity surface was analyzed,the results show that:the temperature of the active region of the front cavity decreases obviously with the increase of the width of the current non-injected region,but after increased to 60 ?m,the change in temperature leveling off;For the 60?m wide non-injection window,the light intensity at the front cavity surface decreases from 1.977×108 W/cm2 to 1.586×108 W/cm2,which decreases by 19.8%,and the carrier concentration decreases from 8.12×1017cm-1 to 6.89×1017 cm-1,which decreases by 12.16%.The light absorption and carrier concentration at the cavity surface can be effectively reduced by introducing the current non-injection window,which provides a design reference for optimizing the non-injection window structure and improving the COD threshold power.Secondly,for the 976nm ADCH semiconductor laser designed in this paper,the device peak wavelength of the laser was 977.48nm.At 70?,the threshold current of the device increases to 1.32A,the slope efficiency decreases to 0.853W/A,and the output power decreases to 13.04W.The characteristic temperature calculated is 160K,and the spectral redshift is 0.4nm/?.The optoelectronic characteristics of different cavity lengths were tested,and the internal quantum efficiency is 96.15%and the internal loss is 0.129cm"1.Finally,according to the design of the device structure and characteristic test results,the corresponding parameters are extracted,and based on the rate equation,the equivalent circuit model of 976nm high-power quantum well laser is established for DC characteristic simulation.The established circuit model can well match the LIV characteristics and temperature characteristics of the actual device.It can provide a practical laser circuit model for the design of high power semiconductor laser driving power supply.