年間 12 号発行
ISSN 印刷: 0040-2508
ISSN オンライン: 1943-6009
Indexed in
INFLUENCE OF THE REFRACTIVE INEX ANISOTROPY ON THE OPTICAL AND EMISSION CHARACTERISTICS OF LASER MATRICES BASED ON THE DYE-DOPED POLYURETHANES
要約
Recently, increased interest has been shown toward investigations oriented at the creation of efficient solid-state dye lasers. The majority of these investigations are focused on synthesizing solid active media on the basis of transparent polymers of various chemical natures. One class of the polymers that can be used in the laser technologies is represented by the polyurethane and its derivatives. The polyurethane media have been studied much poorly as compared with other kinds of the polymeric media. In particular, this concerns their optical properties. The study is aimed at analyzing the causes for occurrence of refractive index anisotropy in active polyurethane materials and investigating its influence on the optical and emission characteristics of laser matrices. It is ascertained that the optically anisotropic state of the medium is called forth by both the internal stresses of the polyurethane due to intermolecular interaction and thermal stresses induced by the powerful pumping. It is shown that the optical anisotropy results in the local birefringence effect in the media. The influence of the birefringence induced by the transverse pumping on the laser emission polarization is investigated. It is shown that under such conditions the active polyurethane elements generate a polarized emission even being excited by unpolarized light.