Research And Preparation Of 940nm High Power LD

High power LDs have important application prospects in fields such as optical pumping,medical field,laser technology,LD?Semiconductor Laser?marking machine,digital communication technology,and cutting technology.Among them,when the 940nm LD is used as an excitation source,the Yb:YAG solid state laser can generate a 515nm wavelength laser after being doubled by the 1030nm optical wave,which is very close to the argon-ion laser's 514nm wavelength,so it can replace the argon ion laser.At the same time,since the 940nm LD has a wide absorption peak for a Yb-doped pump source and has obvious temperature stability advantages,it can work stably under a continuous output environment,and thus has a great potential for development.For this reason,high-power LDs have been continuously applied and developed,and continuously increasing the output power of LD is an important research direction.In this paper,the following work was done to prepare a 940nm high power LD:1.Explain the working principle of MOCVD equipment,optimize the structure of epitaxial wafers,and use MOCVD equipment to grow the designed large-cavity asymmetric structural epitaxial wafer.The designed large cavity structure can effectively increase the lateral size of the spot and increase the cavitation damage?COMD?level of the cavity surface.The asymmetrical waveguide structure can suppress the lasing of the high-order mode.According to the fitting data,the quantum efficiency of the laser produced by this epitaxial wafer is as high as 99.1%and the internal loss is only 0.21cm^-1.2.Optimize the details of the work process.The traditional process has the characteristics of low yield,unstable performance,and so on,so this article focuses on optimizing the specific details and parameters of the process,such as changing the cleaning solution,optimizing the layout of the photolithography,the temperature of the rapid annealing and the protection of the cavity surface.The performance of the laser was improved,and its yield was increased from the initial 30%to 80%.3.Improve the process of preparing LD.Through the introduction of isolated double trench structure,limiting the lateral expansion of the current,and optimizing the depth and spacing of isolated double trench to reduce the threshold of the LD,and increase its slope efficiency electro-optic conversion efficiency and light output power.The light output power of the device is also increased by studying the effects of the positive and negative die attach on the device performance and using the cavity surface coating process.The single-tube 4mm cavity laser diode prepared was tested at a current of 26.6A with a slope efficiency of 0.78W/A and an output power of20.3W.