부산대학교 도서관

Abstract. Elementary holographic phase gratings can be written in single crystal s of Na[sub 2][Fe(CN)[sub 5]NO].2H[sub 2] O, sodium-nitroprusside, by excitation of metastable electronic states in the blue-green spectral range. For light polarized parallel to the crystallographic a and b axes of the orthorhombic crystal the light-induced modulation of the refractive index reaches change n is approximately equal to 2 x 10[sup -3] at lambda = 514.5 nm. Although the largest population of the metastable states is reached for light polarized parallel to the crystallographic c axis, a photorefractive response is not observed. In contrast to electro-optic photorefractive materials the photorefractive effect depends mono-exponentially on the exposure and on the modulation of the incident light interference pattern. Beam-coupling experiments demonstrate that written gratings are in phase with the interference pattern in correspondence with the fact that the excitation of the metastable electronic states is local. The width of the rocking curve shows that the holographic gratings are written completely over the volume of the crystal. Variations of the wavelengths within the excitation range as well as of... [ABSTRACT FROM AUTHOR]