Pump-probe thermal lens near-infrared spectroscopy and Z-scan study of zinc (tris) thiourea sulfate

Abstract

We demonstrate a novel use of the pump-probe thermal lens spectroscopy and Z-scan techniques for the measurement of the small absorption coefficient in a semiorganic, nonlinear optical crystal zinc (tris) thiourea sulphate. We measure the absorption spectrum and the absolute values of the absorption of the crystal in the near-infrared region (700–980 nm). A maximum absorption coefficient of ∼0.04 cm-1 is reported.