【摘要】 本文详细论述了半导体蓝光激光器的应用前景、国内外研究动态以及量子阱半导体蓝光激光器件的结构与种类等。更多还原

【Abstract】 The purpose of research of beam quality has been discussed in this paper.The essense of measuring beam quality is considering the prerequisite of energy conservation,to define the propagation equation of beam.After analyzing far field diffraction properties of virtual confocal unstable cavity laser beam,it is concluded that the size of central diffraction spot of annular aperture is smaller than that of circular aperture,whose diameter is same as that of annular aperture.The intensity of former,however,is lower than that of latter.Likewise,the more narrow the annular aperture is,the smaller the central spot is.Meanwhile,the lower the intensity is.Additionally,the most of energy has been spread out and the far field divergence angle has been rised.Defining beam width in term of energy percentage does not accord with propagation equation and the second moment of far field diffraction intensity distribution of annular aperture beam is divergent,therefore some basic difficults will be encountered when the beam quality of virtual confocal unstable cavity is evaluated by β and M 2.By the way diffraction-free beam or supper diffraction limiting beam also are discussed.Finally,some possible solutions of evaluating problems of unstable cavity laser beam quality has also been discussed.更多还原