COHERENT POPULATION TRAPPING IN A NONMONOCHROMATIC LASER FIELD

The phenomenon of coherent population trapping (CPT), which arises in a medium due to the action of an electromagnetic field of only one laser with a finite spectral width, is examined. The analytic solution of the nonlinear equation of optical radiation transfer (in terms of frequency components) is obtained for arbitrary laser radiation and light absorption spectral contours. The conditions of the CPT observation are determined. It was shown, that the law of decrease of laser radiation integrated intensity is linear as a function of the optical length, when CPT occurs. This linear type of intensity decrease is independent of laser field and absorption contour shapes. The propagation of each spectral component is determined by the totality of all the others, i.e., "frequency memory" takes place.