Determination of Third Order Nonlinear Optical Parameters-Nonlinear Refraction, Nonlinear Absorption and Susceptibility of Guanidinium Benzenesulfonate Organic Single Crystal with a Q-Switched Nd-YAG Laser at Two Excitation Wavelengths

Abstract

Third-order nonlinear optical behavior, i.e., nonlinear refraction (n₂), absorption coefficient (β), and third-order susceptibility χ⁽³⁾of an organic single crystal guanidinium benzenesulfonate are investigated under the excitation of Q-switched Nd-YAG laser pulsed radiations (532 nm and 1064 nm) by Z-scan method at different intensities. The calculated values of (β), (n₂) and χ⁽³⁾ at 532 nm are from 0.38(cm/GW) to 0.65(cm/GW), −3.36 × 10⁻⁷(cm²/GW) to −5.37 × 10⁻⁷(cm²/GW) and 1.28 × 10⁻¹¹ (esu) to 2.20 × 10⁻¹¹ (esu) at the beam intensities of 0.38 GW/cm² to 0.92 GW/cm² respectively while the values of (β), (n₂) and χ⁽³⁾ at 1064 nm are from 0.45(cm/GW) to 0.65 (cm/GW), −3.36 × 10⁻⁷(cm²/GW) to −5.82 × 10⁻⁷(cm/GW) and 0.38 to 0.92 GW cm⁻² respectively at the beam intensities of 0.52 to 0.93 GW cm⁻². It is seen that crystal possesses a positive absorption coefficient, negative nonlinearity, and RSA, and can be a potential candidate for different practical device applications.