The Design Of High Power Semiconductor Laser With Multiple Active Layers Integrated By Tunnel Junctions

High power semiconductor lasers are widely used in communication, surgery, printing, laser manufacture and optical pump. Especially in modern war, it is importent to apply it to the high precision weapon. But for traditional laser, the output optical power, which is increased by increasing the injecting current, will be limited by the electro-thermal destroy and the catastrophic optical damage(COD) at high optical power. Besides, its worse equality of light beam compared to the solid state laser and its low emitting efficiency also have a great influence on the working characteristics of semiconductor laser and narrow its latent applications. The high efficiency and high power semiconductor laser with multi-active regions, which are integrated by reverse biased tunnel junctions can resolve the heat problems in theory and overcome these shortcomings. So study and improve the novel laser have a important significance.In this letter, a detailed analysis of the working mechanism and characteristics of high power semi conductor laser with multiple active layers integrated by tunnel junctions was first made, and the math expression of efficiency was given.The novel laser has broken the restriction that internal quantum efficiency of normal laser is less than 1, and can multiply the internal quantum efficiency without changing working current. Thus light output power is increased but the joule heat is almost the same, so it can efficaciously enhance the COD level. Secondly, the characteristics of tunnel junction, which is the important part of this mechanism, was also measured and analyzed. And the effects of inducing the tunnel junction to the laser were stressed. In order to exactly control the doping lever of GaAs material, grow high performance tunnel junction, we have analyzed the dependency of doping level on growth parameters such as growth temperature, Ⅴ/Ⅲ ratio and doping molecular flow in base on the growth experiment result. When designing the novel laser, we optimized the material structure base on the simulation result of the lasing mode and the distribution of the optical field. In order to control the diffusion current, we designed two grooves structure. Quantum-well laser with two active layers integrated by tunnel junction materials was grown,the peak wavelength is 918.2nm. Measurements show that the device has a threshold current of 230 mA, the slop efficiency of 0.93W/A without coating, about double of traditional laser.