Study Of Beam Properties Of High Power Laser Diodes

Semiconductor laser has important significance in practical application, it has small size, low power consumption, long life, high electro-optical conversion efficiency, wide wavelength range, and also can lase laser by using simple injection current. At the same time its working voltage and current can compatible with integrated circuit, so it can be used for monolithic integration, and also be used as much as GHz frequency direct current modulation for high speed modulation laser output. Based on the above advantages, semiconductor laser are widely used in laser fuse, laser guidance and ranging, laser printer, laser warning, laser micro machining and laser surgery.With the development of semiconductor laser, we put forward higher standards on the performance of high power semiconductor laser, it has become the research focus at the stage to increase the output power of semiconductor laser and improve semiconductor laser beam quality. Especially for high power semiconductor lasers work under large current, guarantee its output power at the same time also need to ensure the quality of the output beam of light transmission, in the process of application, the coupling efficiency which coupled to optical fiber does not vary with the change of the injection current. This paper is mainly aimed at studying of 980 nm light field characteristics of high power semiconductor laser. In the process of the research, we found that the near-field facula movement when output beam at laser beam test, and with the increase of injection current, light beat phenomenon is more obvious. Light beat phenomenon explains that the internal model of semiconductor laser is unsteadiness, influence the output beam quality of semiconductor laser, result in a declining of semiconductor laser output power and the decline of optical fiber coupling efficiency. This paper designs a kind of groove structure to improve near-field facula beat phenomenon, stable coupling efficiency. This paper’s research work mainly includes:(1) Design and preparation of the 980-nm asymmetric large optical cavity single light of the high power semiconductor laser epitaxial wafer, it’s large optical cavity structure of laser light area can improve the high power semiconductor laser COD(catastrophic optical damage) threshold, at the same time, the asymmetric waveguide structure suppresses the high-order mode lasing.(2) This paper designs a groove structure, namely the ridge shape of semiconductor laser lead hole adopted in 5?m wide groove for cycle. Groove structure of semiconductor laser can be effectively limited carriers in the trench, reduce lateral "light" shift, makes the cavity indoor model stably, inhibition of near-field light phenomenon.(3) Using correlation plan, compare Groove laser with ordinary structure of laser. Testing above two different structure of semiconductor lasers, obtain the P-I curve、the power before and after coupling and the coupling efficiency. The stable coupling efficiency and the consistency of the power, shows that the internal mode of groove structure is more stable, can effectively suppress lateral wire shift and facula beat phenomenon.(4) In this paper, 180 packaged without groove structure devices do the reliability test, there are 72 devises output power have not changed basically. This paper analyzed the failure device, concludes that the main reason of the failure laser is film tearing when separating film.