Photodynamics in Thin-Layered Structures of Laser Beam Limiters pra-0103

Full Title Photodynamics and Optical Bistability in Thin-Layered Structures of Laser Beam Limiters Tech Area / Field

• MAT-CER: Materials / Ceramics

• PHY-OPL: Physics / Optics and Lasers

• CHE-RAD: Chemistry / Photo and Radiation Chemistry

Brief Description of Technology One of today’s important problems is the develpment of wide-band quick-acting laser beam limiters for eye protection. Traditional optical elements (filters, phototriplex glasses) do not show a quick response and are not wide-band.

Research on the bistability of nonlinear optical media [1], on the interaction of laser beams with solutions of organic compounds [2], on solution thermodynamics [3], and on the bistability of phase transitions in dynamic thin-filmed multilayer VO₂ mirrors [4], carried out earlier at the ILP, is used as the basis for the research proposed here.

We plan to perform research on the photodynamics and optical bistability of nonlinear optical thin-layer structures based on materials containing fullerenes, admixed liquid crystals and vanadium oxides.

Furthermore, we plan to investigate the photodynamics of fullerene systems (including solid solutions), elaborate unusual bistable systems, and study a new effective chiral and nematochiral liquid crystal, which - when mixed with fullerenes - will allow to essentially extend the spectral range of laser limiter operation in visible and almost IR ranges.

Investigation of the amplitude and spatial bistability of phase transitions of new thin-film multilayer VO₂ structures and the study of the newly obtained effect of phase transition under laser beam influence will make it possible to create bistable devices for the IR spectrum range.

Thus the study of the photodynamics and unusually composed bistable structures allows to create a wide range of nonlinear, reversible quick-acting laser beam limiters, involving wavelengths from 0.4 to12 m, which have the dynamic contrast that are necessary for eye protection.

Legal Aspects None.

Special Facilities in Use and Their Specifications The facilities used in the investigations are: - laser radiation of the second and third harmonic Nd:YAG in the nanosec range; - a facility for the study of the kinetics of fast processes on Nd:YAG lasers, up to several femtosec; - a "Module" device for the study of bistable phase transition in the IR range on the basis of a CO₂ laser.

Scientific Papers 1. N.N. Rosanov. Optical bistability and hysteresis in distributed nonlinear systems. Moscow, "Nauka" 1997.

2. V.V. Danilov, Yu.T. Masurenko, S.I. Vorontzova. Anti-Stokes excitation of dyes by high-power radiation. Optics Commun. 1973, v. 9, p. 283.

3. V.P. Belousov, M.Yu. Panov. Thermodynamic properties of aqueous solutions of organic substances. CRC Press. Boca Raton, Ann Arbor, London, Tokyo. 1994, 368 p.

4. O.B. Danilov, V.V. Danilov, V.V. Lubimov, N.N. Rosanov, A.I. Sidorov. CO₂ Lasers with flexible parameters and their use in technological applications. NATO ASI Series. Klawer Acad. Publ. 1996, S. 3: High Technology. V.10, pp. 301-322.