Enhancement of the sensitivity of intracavity laser spectroscopy by a nonlinear absorber

A semiquantitative analysis is used to show that the use of a saturable filter for the enhancement of the spectral contrast inside the resonator of a wide-band flashlamp-pumped dye laser makes it possible to remove the principal restriction on the sensitivity of the method of intracavity laser spectroscopy associated with the duration of the laser pulses. In this way it is possible to increase the sensitivity by between one and two orders of magnitude. It is reported that a cell with a solution of cresyl violet located at the caustic of a flashlamp-pumped dye laser increased the depth of the dip in the emission spectrum by a factor of 30 at the expense of a slight overall reduction in the signal intensity.