The results show that, when the Fresnel number is small, the low-loss mode field distribution is the low-order mode, on the contrary, the low-loss mode field distribution is the high order mode.

• 结果显示，模式分布类似于稳定腔的模式，并且腔的菲涅尔数越小，模式阶数越低，当菲涅尔数合适时，可实现基模振荡。