双光子激光统计性质——无细致平衡统计

STATISTICS OF TWO-PHOTON IASER——the system without detailed balance

本文研究具有单光子损失机制不服从细致平衡的简并双光子激光(Ⅰ)。约化密度矩阵的P表示在一定条件下满足Fokker—Planck方程,由次可确定Ⅰ的统计性质。与单光子激光(S)和具有双光子损失机制的简并双光子激光(Ⅱ)相应结果相比较表明:Ⅰ和Ⅱ的稳态平均光子数比S高得多,S、Ⅰ和Ⅱ所需原子数反转成递增序,Ⅰ、S和Ⅱ的线宽成递增序,而且相差甚大。

The dengenerate two-photon laser(Ⅰ)with single photon loss mechanism is studied. The P representation distribution function of the reduced-density operator of the twophoton laser is shown to satisfy a Fokker-Planck epuation from which the statistical properties are determined. The comparison between these and the corresponding ones of the singlephoton laser (S) and the two-photon laser (Ⅱ)with two-photon loss mechanism,shows that,the average photon number in the steady state is by far higher of Ⅰ and Ⅱ than of S, the inversions for all atoms of S, Ⅰ and Ⅱ increase remarkably successively,and so do the line-widths of Ⅰ ,S and Ⅱ.