Nanosize crystals (quantum dots) of semiconductor embedded in a glass matrix are materials of great interest, due to the controllable optical properties of the semiconductor. Due to the finite size and confinement of the nanocrystals, their linear and nonlinear optical properties change drastically. The distribution of nanocrystal sizes in the mateirla is one of the important parameters, which effects the sharpness of the optical absorption spectrum. We have been exploring photphate-fluorine based glass matrices, doped with CdS_xSe_x. In this matrix and concentration of semiconductor can be increased by an order of magnitude and the annealing and coalescence temperatures are a few hundred degrees below those for silicate glasses thus making glass processing much simpler. We will describe our measurements of the linear and nonlinear properties of these glasses. In particular the measurement of X~(3) by four wave mixing will be reported.Higher order nonlinear properties, the saturation of the nonlinearity and the onset of irreversible optical changes in the material will be described and interpreted.
展开▼
