INTRACAVITY LASER SPECTROSCOPY WITH VIBRONIC SOLID-STATE LASERS .1. SPECTROTEMPORAL TRANSIENT-BEHAVIOR OF A TI-SAPPHIRE LASER

Spectrotemporal dynamics and the sensitivity limit of intracavity absorption in the case of a Ti:sapphire laser during buildup and relaxation oscillations are investigated. Both theoretical and experimental approaches confirm that the generation time, a crucial parameter in an intracavity absorption experiment, must be modified. During the transient period relaxation oscillations appear to have no effect on the regular linear growth of the absorption. The birefringence Limits the sensitivity of the detection to an absorption coefficient of the order of 10(-8) cm(-1) A special cut of the crystal is suggested to overcome this technical limitation. It is shown that the ultimate limitation, imposed by spontaneous emission, promises a very high sensitivity, equivalent to an absorption path length of several hundred thousand kilometers. An example of the absorption of the 4(2) stretch band of CHD3 is presented.