Time domain study on cavity ring-down signals from a fabry-pcrot cavity under pulsed laser excitations

We present an analysis on ring-down signals produced by a pulsed laser excitation of a Fabry-Pérot cavity. Main features of a ring-down signal arc numerically investigated by taking time domain approach under a simplistic assumption that a Fourier-transform-limited Gaussian laser pulse be injected to a stable empty cavity with complete mode-match to the lowest cavity transverse mode. Temporal aspects and output coupling efficiency of a ring-down signal are obtained with excitation pulse duration and cavity parameters taken into account. Clear physical insight is allowed in the time domain description especially for the forefront transient peak and the inherent intensity modulation which are found to be superimposed on a ring-down signal.