Abstract:
An experimental method was developed for the determination of the rate of relaxation of the 4I11/2 state and of the absorption cross section of the 4I11/2–4F3/2 transition. These parameters were deduced from the dependences of the intensity of the λ = 0.88 μ luminescence, excited as a result of the 4I11/2–4F3/2 transition by laser pulses of λ = 1.06 μ wavelength, on the energy density and duration of the laser pulses. Estimates of the relaxation time obtained for the investigated silicate (GLS-1) and phosphate (LGS-40, LGS-I) glasses, and also for a liquid based on POCl3-SnCl4, gave τ21 < 2 nsec. A considerable increase in the population of the 4I11/2 level occurred as a result of the Raman scattering of high-power coherent radiation by vibrations of the PO4 group.