Raman Spectroscopic Study of Very-Low-Frequency Vibrational Modes of CdSxSe1-x Nanocrystallite. Effect of Laser Induced Crystallization on Cubic Optical Nonlinearity

Very-low-frequency bands of Raman scattering of CdSxSe1-x fine particle was employed to investigate laser induced crystallization which is responsible for reflectivity change of optical phase-conjugation signal. The laser induced reflectivity change of phase-conjugated signal was interpreted in terms of growth of radii of nanoparticles monitored by very-lowfrequency Raman bands. Essentially, the reflectivity of phase-conjugated signal from CdSxSe1-x nanoparticle doped glass was decreased by the laser induced crystal growth. Temporarily enhanced reflectivity was shortly commented. Excitonic excitation effect on optical phonon (LO) spectra was also observed.