| Popis: |
GaSe-type crystals have attracted increasing attention because of pronounced structural anisotropy, unique optical and Nonlinear Optical Properties, which may lead to numerous applications in light generation (second harmonics and tuning in a wide transparency range of λ= 1÷20 μm) and optoelectronics (radiation detectors, photovoltaic energy converters, photo-resistors, light modulators etc.). In the present work, damage threshold of the Bridgman grown GaSe and its structural analogs ((GaSe1-x Sx (where 0 ≤x ≤0.25, InSe and GaTe)), have been investigated under IR τ = 5 ns pulses (λ= 1.064 μm) of "QUANTELL Brilliant b" laser (pulse energy ~ 850 mJ, f = 20 Hz). For all studied crystals occurrence of local micro defects and pulse induced heating were identified to be responsible for damage threshold mechanism. Results for GaSe obtained in the present work are in good agreement with published in literature for damage threshold excited with laser lines in the spectral range of λ= 1.1 ÷ 2.9 μm lines of the Optical Parametric Generator. The values of damage threshold for solid solutions of GaSe1-x Sx, InSe and GaTe crystals are reported for the first time. |
