大功率半导体激光器远场特性研究

Far-field Characteristics of High Power Laser Diode

由于半导体激光器输出光束的不对称性 ,使得它在许多应用过程中必须采用特殊的光学系统进行光束整形。在设计光学系统的光学元件及进行光学耦合时需要了解激光器的远场特性。通过用量子阱激光器的解理面上的边界条件解亥姆霍兹方程 ,获得关于远场强度分布、光束散角 ,并用计算机给出各种理论曲线及数据。用自行设计制作的测试装置测量 ,获得激光器的远场分布曲线给出了测试数据。计算机给出的理论远场分布曲线与实验测试获得的远场分布曲线完全一致。

In recent years, the high power lasers have been widely applied in military, industry, medicine, such as in the strong laser weapon, laser detonator, laser guidance, precise machine processes, light storage, light pumps, laser chemistry, laser medicine and so on. Because of the asymmetry of semiconductor laser output beam, the beam must be shaped by optical system in some cases. The far-field characteristics of laser out put must be understood during designing the optical element and optical coupling.Furthermore, optical-field characteristics of laser cavity can be obtained by correct far-field modal with measure data. In this project,the Helmholtz equation was solved by the cleavage facet boundary condition of quantum-well laser. So the density distribution of far-field and divergence angle of beam were obtained. The theoretical curves and data obtained by computation were ploted also. The curve of the far-field distribution of laser and the measure data by the semiconducter laser all-parameter measurement meter, including the far-field intensity profile and the beam divergence angle. The experimental results are in agreement with the theory. The laser sample used in the experimental measurement is 82~# laser diode, CW output power as 2.01 W, operating current as 10.53 A, operating voltage as 1.7 V, slope efficiency as 1.01 W/A, center wavelength as 801.8 nm, spectral width 2 nm, emitting dimensions 150 μm×1 μm, divergence angle of perpendicular junction plan as 28.8°, divergence angle of parallel junction plane as 7.5°, the experimental measurement performed with a separation distance of 50 mm from the laser cavity surface. The results showed that the theoretical far-field intensity distribution curve is in accordance with the experimental measurement data basically.