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 (n 2 ), 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), (n 2 ) and χ (3) at 532 nm are from 0.38(cm/GW) to 0.65(cm/GW), −3.36 × 10 −7 (cm 2 /GW) to −5.37 × 10 −7 (cm 2 /GW) and 1.28 × 10 −11 (esu) to 2.20 × 10 −11 (esu) at the beam intensities of 0.38 GW/cm 2 to 0.92 GW/cm 2 respectively while the values of (β), (n 2 ) and χ (3) at 1064 nm are from 0.45(cm/GW) to 0.65 (cm/GW), −3.36 × 10 −7 (cm 2 /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.