Two photon absorption characteristics of bulk GaTe crystal

We have investigated the structural and optical properties of bulk GaTe crystal grown by vertical Bridgman method. Two photon absorption (TPA) properties of GaTe crystal have been investigated by the open aperture Z-scan technique under 1064 nm wavelength with 4 ns or 65 ps pulse durations. The TPA coefficients are greater in ns regime than that of ps regime. Upon increasing intensity of incident light from 5.02×107 W/cm2 to 1.07×108 W/cm2, the TPA coefficients increased from 3.47×10−6 cm/W to 8.53×10−6 cm/W for nanosecond excitation. Similarly, when intensity of incident light was increased from 6.81×108 W/cm2 to 9.94×108 W/cm2 the TPA coefficients increased from 3.53×10−7 cm/W to 6.83×10−7 cm/W for picosecond excitation. Measured TPA coefficient of GaTe crystal is larger than that of GaSe and GaS layered crystals.

► TPA properties of GaTe semiconductor crystal was investigated for the first time. ► The effect of pulse durations to the TPA coefficient was investigated and compared. ► GaTe crystal had larger TPA coefficients compared to GaSe and GaS layered crystals. ► GaTe crystal is thought to be an important candidate as light converter and optical limiter material.