Investigation of bleaching and relaxation of a stable passive neodymium-laser switch utilizing a phthalocyanine dye

Investigations were made of the characteristics of a stable bleachable switch (for neodymium lasers) utilizing dye No.1051. Measurements were made of the transmission as a function of the incident radiation density for different pulse durations. The relaxation kinetics of the solution was investigated in the range of several tens of nanoseconds and in the microsecond range. The relaxation process included two successive stages of different durations. It was established that the relative contribution of the slow component depended on the energy density of the exciting pulses, its lifetime was measured, and the induced absorption spectrum was determined. The composition under study is characterized by a low residual absorption and a reduced relaxation time of the long-lived state.