Abstract
The use of passive shutters to control the duration of the light pulses is an important aspect in the miniature and microchip lasers. One of the key spectroscopic characteristics which determine the properties of the material, which can be used as a passive shutter is relaxation time of its bleached state.We describe a device for determination of relaxation time of the bleached state in optical materials by the «pump-probe» method in the sub-μs time domain. This device allows one to determine relaxation times for materials which absorb at the light wavelength of 1.5 μm, e.g., materials doped with cobalt ions Co 2+ . The results of test examinations of the device are described, and the relaxation time of the bleached state of Co2+ ions is measured for a novel material – transparent glass-ceramics with Co 2+ :Ga 2 O 3 nanophase – amounting to 190 ± 6 ns.