Observation of two Z(3) exciton resonances in CuCl-doped non-linear optical glass

Non-linear optical properties of CuCl-doped soda-lime aluminoborosilicate glass system have been investigated using the absorption saturation measurement and the degenerate four wave mixing method. The non-linear optical properties were confirmed by the saturation of the absorption coefficient and the blue shift with increase of laser intensity. Two Z(3) exciton resonances of the CuCl crystallites in the samples heat treated at 600 degrees C for 10 h were observed when the laser intensity was less than 10(3) kW/cm(2) at 77 K. The unique two Z(3) exciton peaks are attributed to a bimodal distribution in sizes of CuCl crystallites due to the phase separation. The third-order non-linear susceptibilities, chi((3)), obtained by the absorption saturation measurement showed large peak values at two Z(3) exciton resonances. The chi((3)) values of similar to 3 x 10(-8) esu obtained by the absorption saturation method were in good agreement with directly measured values by the degenerate four wave mixing method.