Abstract

The physical nature of the backward-stimulated emission can be understood by considering the angular distribution of the total radiation from a set of atomic dipoles driven by an intense laser beam. From the classical point of view, the backward-stimulated emission is simply a reflection from the interface between a dielectric and a gain medium from the mismatch in the imaginary parts of their indices of refraction. For bulk gain structure, backward-stimulated emission is usually too weak to be noticed. However, in the case of a gain layer much thinner than a wavelength or a periodic thin gain structure with a spacing of λ/2, the backward-stimulated emission is enhanced and can be as large as the forward stimulated emission in terms of the amplitude of radiation field.¹

© 1991 Optical Society of America