PROJECT TITLE :

Direct Measurement of Temporal Transmission Distribution of a Saturable Absorber in a Passively Q-Switched Laser

ABSTRACT:

An in situ temporal decay and spatial distribution of the transmission of a Cr4+:YAG saturable absorber in a passively Q-switched Nd:YAG laser were measured simultaneously by a scanning transmission centered laser beam technique. An excited ion decay time of 4 μs and a high hat (saturated) transmission distribution were clearly observed. The ratio of the bottom-state absorption cross section and also the excited-state absorption cross section (σSAπ/σESAπ) for π-polarized light to the S4 native symmetry axis of Cr4+ center was measured at approximately four.one-four.2. Using a theoretical fitting of the transmission distributions, we tend to found the ground-state absorption cross sections to be at one × 10-17 and a pair of.3 × ten-19 cm2 for π and for σ-polarized lightweight to the S4 native symmetry axis of Cr4+ center, respectively. The worth of the excited-state absorption cross section was additionally estimated correspond to two.four × 10-18 cm2.