Structure Design And Epitaxy Growth Of High Power Semiconductor Laser Diodes Emitting At 808nm And 905nm

Due to the advantages including small size, light weight, long life, high coversion efficiency, high reliability and so on, high-power semiconductor laser diodes have been widely applied in the field of industry, medical and military, for instance, fiber-optic communications, data storage, laser fuze, holographic technology, scan to print and entertainments, etc. high-power semiconductor laser diodes emitting at 808 nm are always used as pump-source for Nd:YAG, Er-doped and Yb-doped optical fiber amplifiers and lasers, which have the high slope efficiency and conversion efficiency. 905 nm high-power semiconductor laser diodes have no harm to the eyes, so it have great potential in the application of alignment, ranging and velocity measurement.In this paper, the semiconductor laser diodes with large optical cavity were designed, which can not only improve the catastrophic optical mirror damage threshold, but also can inhibit the lasing of higher-order mode. The quantum well of 808 nm semiconductor laser diodes were adopted In Al Ga As and Ga As P respectively, and the use of Al-free Ga As P quantum well is beneficial to improve the reliability of the device. 905 nm semiconductor lasers were adopted multi active region tunnel cascade structure, which can significantly improve the internal quantum efficiency of the laser.This paper focus on the structure design and epitaxial growth of semiconductor laser diodes emitting at 808 nm and 905 nm, and the research was carried out from the following aspects:Firstly, introduce the development history and research status of semiconductor laser dioses.Secondly, expound the principle and composition of metal organic chemical vapor deposition(MOCVD) system. The laboratory used D125 LP-MOCVD system for the epitaxial growth of semiconductor laser diodes. The most used measurements are PLM-100 photoluminescence of Philips and PN4400 electic C-V system of Accent.Then, introduce the design flow of strained quantum well laser diodes, which includes the caculation of strained quantum well band gap, the caculation of band edge, and the relatioship between lasing wavelength, quantum well material composition and quantum well width. In order to determine the material component and the well width of quantum well, the quantum well was modeled using transfer matrix method based on the model of Kohn-Luttinger Hamiltonian. The quantum well of 808 nm laser diode were adopted 10 nm In0.14Al0.11Ga0.75 As and 12 nm Ga As0.84P0.16, respectively. The active region of 905 nm laser diode were adopted 7nm In0.1Ga0.9As double quantum wells. The waveguide layers and the barrier were adopted Al0.3Ga0.7As, the cladding layers were adopted Al0.5Ga0.5As. On the basis of above, the active region structures were grown by MOCVD, and optimized the epitaxial structure and conditions according to the results of PL.Finally, based on the optimized structure of quantum well, increase the thickness of waveguide-layer, cladding-layer and cap-layer, and take appropriate doping in cladding and cap layers. After the growth of the structure that was carried out by using the MOCVD, then, laser diode chip was fabricated after photolithography and etching, deposition, sputtering, cleavage, coating, sintering, welding, packaging and other post process. At the same time, the performance of the chip was reflected by photoelectric property test.