充单同位素Ne的HeNe激光器的一种模式竞争与跳变

在一支HeNe激光器腔长增大的过程中观察了其偏振态的变化，发现它的一种偏振态表现为常亮，另一种偏振态表现为常暗，只有换模时，后者才有机会振荡但又会迅速熄灭，同时它们的光强功率也呈反向变化，这说明两种偏振态的模存在强烈的竞争，且在换模过程中发生了模式跳变，目前尚无对这种现象的具体报道。研究了激光器两种正交模式在腔长调谐时的纵模特性及两种偏振态的光强调谐曲线在频差调整前后的变化，由分析可知:增益介质仅为单同位素Ne是引起两种正交模式偏振异常的原因，并阐述了单同位素Ne对模式竞争的影响。

A mode competition and jump of HeNe laser with monoistopic Ne

The change of the polarization state of a HeNe laser is observed when the cavity length is increasing, it is found that one of its polarized state is always bright, and the other polarized state is always dark. Only in process of mode conversion, the latter has opportunity to oscillate but extinguish immediately, and at the same time their power changes of light intensity in the opposite direction. The phenomenon above shows that there is strong competition between two modes of dual-polarized state as well as the mode jump occurs in the process of mode conversion, but there have been no specific report on this phenomenon. The longitudinal mode characteristic and the change of dual-polarized light intensity curve before and after frequency difference modulation of laser were studied. From the analysis, it is found that gain medium being only monoisotope Ne is the reason which cause the polarization abnormality of the orthogonal modes, and the influence of the monoisotopic Ne on mode competition was also expounded.