CsLiB6O10 crystallites embedded into the photopolymer matrices as promising materials for acoustically induced electrooptics

Acoustically induced linear electrooptics effects (LEOE) in CsLiB6O10 (CLBO ) nanocrystallites incorporated into the olygoether photopolymer matrices h ave been revealed at liquid helium temperature (4.2 K). The LEOE has been m easured for the source wavelength of a He-Ne laser (lambda = 0.63 mum). Wit h increasing acoustical power, the LEOE signal increases and achieves its m aximum at an acoustical intensity of about 18.5 W cm(-2) and a frequency of about 14 kHz. The value of the LEOE r(222) tensor component was comparable with that for the traditional nonlinear optical crystals, such as KH2PO4 K TiOPO4 and LiNbO3. With decreasing temperature (below 25 K), the acoustical ly induced LEOE signal strongly increases. A correlation between the acoust ically nonlinear optical response and low-frequency Raman intensities has b een found. The maximal acoustically induced SHG has been observed for the n anocrystallite concentration of about 3.1% (in weight units) and nanocrysta llite sizes lying within 35-40 nm. The LEOE tensor coefficients were larger than for the bulk CLBO crystals (at least 21%). Advantages and drawbacks o f the presented model were discussed. The origin of the observed phenomena is explained on the ground of the ab initio band energy calculations taking into account anharmonic electron-phonon interactions. (C) 2001 Elsevier Sc ience B.V. All rights reserved.