Solid active media for tunable lasers on the basis of dye-doped polyurethanes

Abstract

Subject and purpose. This article is devoted to a brief review of the main results of the research cycle aimed at developing solid active media based on dye-activated polyurethane compounds. The ultimate goal of these studies was the creation of solid-state active elements that make it possible to realize a wide-band solid-state dye laser (SSDL), which emits frequency-tunable radiation with a microsecond pulse duration. Methods and methodology. The problem was solved mainly by experimental methods. At the same time, the studies carried out included a full range of works, starting with the production of samples of solid-state active media to study the generation characteristics of the active elements created. Results. In the course of the work, laser-active media based on industrial polyurethanes of various grades activated with Rhodamin 6G, Sulforhodamine 101, Oxazin 17, and Oxazin 1 dyes have been created and their spectral-luminescent characteristics have been studied. Experimental samples of laser matrices are made. The optical properties of the media created are studied and the influence of the technique of making samples on the nature of possible distortions of their optical homogeneity is determined. The emission ability of polyurethane matrices was studied. With transverse monochromatic excitation laser emission was obtained on polyurethane matrices with an efficiency of 12 to 26% and energies from 23 to 127 mJ. Radiation resistance and possible service life of polyurethane media have been investigated The thermo-optical properties of polyurethane active media and their effect on the directivity of SSDL radiation are studied. The effect of induced birefringence, which occurs under conditions of asymmetric pumping of microsecond duration, is observed. It was found that under such conditions, polyurethane active elements emits polarized radiation even when excited by depolarized light. A possibilities of narrowing and tuning the emission spectrum of polyurethane matrices in dispersion resonators with angular and amplitude type of selection are investigated. The laboratory model of a tunable SSDL with replaceable polyurethane laser elements, generating a pulsed radiation of a microsecond duration in the spectral range of 565...700 nm is created and tested. Conclusions. The results of the performed studies allow to conclude that industrial polyurethane compounds can be successfully used as solid media for active elements of SSDL.

Keywords

• polyurethane active medium
• solid-state dye laser