Optical pumping method and apparatus

Abstract

In order to avoid problems associated with thermal distortion, loss of energy, and destruction of system components, the invention provides a means for producing, for the first time, high repetition rate, high power pulses while avoiding thermal distortion and its attendant difficulties. The invention provides the ability to remove heat generated from the gain media (lasant material) and to repeatedly extract energy from the media without the accumulation of heat in the media which causes thermal distortions. The invention avoids thermal distortions by pumping an unheated gain region every time an optical pulse is incident thereon. In one aspect, the gain media is essentially uniformly pumped using an essentially instantaneous uniform spatial profile provided by a multi-mode oscillator. The resulting instantaneous uniform temperature profile does not create thermal gradients, thus, no thermal distortions occur. In the invention, the total time duration of pumping and lasing or amplification takes place while the thermal profile remains uniform in the region of the media in the beam path. Thus, no thermal distortions occur during the time of pumping and lasing or amplification. Heat is preferably extracted at about the same rate it is generated in the lasant material (media).