The possibility of light emission by admixed molecular crystals

Study of the emission spectra of beta,beta'-dinaphthyl ethylene admixtures in naphthalene excited by an ultraviolet laser pulse at 300, 77, and 4.2 K. As pump density is increased, significant changes in the emission spectrum take place, consisting of an ultralinear growth in line intensity and narrowing. A powerful transition oscillator, ordered orientation of the admixture molecules in the lattice, and a heavy concentration of the admixture should ensure stimulated emission even in the absence of a resonator cavity. Possible gain coefficient from 8 to 80 per cm has been estimated.