Spontaneous emission and laser oscillation properties of microcavities containing a dye solution

Abstract
An experimental study on spontaneous and stimulated emission properties of planar optical microcavities confining an organic dye solution is reported. The lasing threshold in an input-output curve became indistinct by decreasing the distance between a pair of dielectric reflectors. The coupling ratio of spontaneous emission into a laser mode was as large as 0.2 for a cavity half a wavelength distance. Differences between the spontaneous emission dominant regime and the stimulated emission dominant regime were also examined with emission spectra and emission lifetime measurements.