Transient differential absorption spectra of solgel glasses that contain copper selenide nanoparticles (NP’s) have been studied with a picosecond pump–probe technique. Oxidation of copper selenide NP’s results in the appearance of an additional absorption band peaked at ∼1 μm, which can be transiently bleached under laser excitation. Excited-state absorption related to mid-gap surface trap states was observed. The absorption recovery time was found to be ∼300 ps. The intensity-dependent transmission of oxidized copper selenide NP’s in solgel glass at 1.08 μm has been measured. Permanent laser-induced absorption changes in the glasses were studied with nanosecond pulses as a function of laser exposure. Passive <i>Q</i> switching of 1.06-μm Nd<sup>3+</sup>:Y<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>, 1.34-μm Nd<sup>3+</sup>:YAlO<sub>3</sub>, and 1.54-μm Er<sup>3+</sup>: glass lasers has been realized with the glasses containing copper selenide NP’s used as saturable absorbers. <i>Q</i>-switched pulses with 100-ns (1.06 μm), 90-ns (1.34 μm), and 60-ns (1.54 μm) pulse widths were obtained.
© 2000 Optical Society of America
K. V. Yumashev, N. N. Posnov, I. A. Denisov, P. V. Prokoshin, V. P. Mikhailov, V. S. Gurin, V. B. Prokopenko, and A. A. Alexeenko, "Nonlinear optical properties of solgel-derived glasses doped with copper selenide nanoparticles," J. Opt. Soc. Am. B 17, 572-579 (2000)