摘要:
本文讨论了n（z,r）=n0（z）+n2（z）r2/re2型复折射率介质中的激光传输问题,给出了激光传输参数（光束半径和波阵面曲率）的演化公式。指出只要存在一定大小的n21,在传输过一段特征距离zc之后,将出现完全光导（即自相似模的传播）,而且自相似模是激光体系的特征模式。其传输参数只与n2有关,而与激光初始参数无关。自相似模必定是高斯球面波,而不是高斯平面波。
Abstract:
Laser beam propagation in the media with complex quadratic index of refraction n = n0 + n2r2/ re2 was investigated. The expressions of beam radius, W(z) and curvature of its wave front, R(z)-1 were obtained. The self-similar (s.s.) mode (perfect guiding) will occure after propagation distance larger than a characteristic length zc, only if n21≠0. The s.s. mode is a eigenmode of media, its propagation parameters W, R-1 are dependent on n2, but independent of the initial value W0, R0-1. At the end, s. s. mode is a Gaussian spherical wave, not the plane wave.
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