Based on theoretical model and calculation method of optical pumped SMMW laser,several problems which should pay attention to in calculation,such as iteration method,resonance characteristic and the feedback property of cavity, Doppler broadening effect and pressure broadening effect etc.

Effect of spectral line with Doppler broadening on optical bistability in a multi mode ring laser;

Ion temperature and recycling particle flow velocity are obtained from Doppler broadening and Doppler shift with Gaussian fitting.

The results show that due to the effect of Doppler broadening the light speed reduction is significant in a range of ±600MHz one-photon detuning.

A detailed analysis is made on the echo s Doppler spread and range spread caused by body target spread,and on their influence on ranging.

The method can significantly reduce the Inter-Carrier Interference (ICI) and additive white Gaussian noise by processing the received pilots both in multipath spread domain and Doppler spread domain.

RTCE is based on forecasting the inherent vulnerabilities to propagation of HF time-varying channel, including multipath delay, Doppler spread, selective fading, interference, so this paper also introduces characteristics of HF channel in the beginning.

Doppler spectral broadening experiment based on virtual instrument