THE PAST, PRESENT, AND FUTURE OF PLASERS - LASING POWDERS

摘要

A lasing effect in powdered luminophores (plasers) was demonstrated in 1986. It was shown that the width of the spectral line narrows, and the emission signal from polycrystalline neodymium or praseodymium doped samples of a powdered luminophore becomes a series of short, intense pulses when resonant optical pulsed pumping exceeds a threshold level; that a narrow emission line of plasers with shapeless particles is situated at the center of the luminescence band, while the emission of plasers with shaped crystalline seeds can have several narrow components across the line of luminescence; and that in mixtures of powders that have different plaser frequencies, the generation frequency depends on the weighted overlap of luminescence spectra. Lasing mechanisms in powders, such as the amplification of spontaneous emission (ASE) and the effect of the distributed feedback due to scattering are discussed herein. Possible ceramic zeolite-like and cavernous plasers, plasers with nonlinear optical effects, lasing foams and emulsions are considered as devices where the effects of photonic crystals on the generation processes in plasers could be observed. Plaser cathode-ray screens with a narrow band (～0.1 nm) and short duration (～1 ns) of luminescence are suggested.