Delayed luminescence spectroscopy and optical phase conjugation in eosin Y-doped sol–gel silica glasses

A triplet state lifetime of 2.0 ms was determined from time-resolved spectroscopic measurements for eosin Y trapped in dry sol–gel silica glasses. Saturation absorption was observed. The saturation intensity was found to be 1.05 W/cm2. Based on the degenerate four-wave mixing arrangement, time transient optical phase conjugation was observed using a low-power continuous-wave argon-ion laser. Transient phase-conjugated reflectivity as high as 10−3 and steady-state reflectivity at 10−4 were achieved. The time behavior of the phase-conjugated reflectivity was found to be in agreement with the model predictions of Silberberg and Bar-Joseph.