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The third order nonlinear optical properties i.e. nonlinear refraction (n 2), absorption coefficient (β) and third order susceptibility χ(3) of glycine zinc sulphate pentahydrate (GZS) semi-organic single crystal was investigated under the excitation of Q-switched Nd-YAG laser pulsed radiations (λ = 532 nm & 1064 nm) by familiar Z-scan method. The values of nonlinear refraction (n 2), at 532 nm were 1.19 × 10−5 (cm2/GW), 2.09 × 10−5 (cm2/GW), 2.27 × 10−5 (cm2/GW), 2.48 × 10−5 (cm2/GW), and 2.55 × 10−5 (cm2/GW) at incident optical beam intensities of 0.76 (GW/cm2), 1.13 (GW/cm2), 1.17 (GW/cm2), 1.63 (GW/cm2) and 1.88 (GW/cm2) respectively while that of values at 1064 nm were 4.31 × 10−5 (cm2/GW), 4.69 × 10−5 (cm2/GW), 5.41 × 10−5 (cm2/GW) and 6.39 × 10−5 (cm2/GW) at incident optical beam intensities of 1.20 (GW/cm2), 1.25 (GW/cm2), 1.32 (GW/cm2) and 1.38 (GW/cm2) respectively. The values of nonlinear absorption coefficient (β) at 532 nm were −1.45 (cm/GW), −0.79 (cm/GW), −0.5 (cm/GW), 0.12 (cm/GW) and 0.64 (cm/GW) at incident optical beam intensities of 0.76 (GW/cm2), 1.13 (GW/cm2), 1.17 (GW/cm2), 1.63 (GW/cm2) and 1.88 (GW/cm2) respectively while that of values at 1064 nm were 0.62 (cm/GW), 0.74 (cm/GW), 0.77 (cm/GW) and 0.81 (cm/GW) at incident optical beam intensities of 1.20 (GW/cm2), 1.25 (GW/cm2), 1.32 (GW/cm2) and 1.38 (GW/cm2) respectively. The values of third order susceptibilities χ(3) at 532 nm were 0.83 × 10−12 (esu), 1.32 × 10−12 (esu), 1.42 × 10−12 (esu), 1.55 × 10−12 (esu) and 1.56 × 10−12 (esu) at intensities of 0.76 (GW/cm2), 1.13 (GW/cm2), 1.17 (GW/cm2), 1.63 (GW/cm2) and 1.88 (GW/cm2) respectively while that of values at 1064 nm were 2.71 × 10−12 (esu), 2.96 × 10−12 (esu), 3.4 × 10−12 (esu) and 4.02 × 10−12 (esu) at incident optical beam intensities of 1.20 (GW/cm2), 1.25 (GW/cm2), 1.32 (GW/cm2) and 1.38 (GW/cm2) respectively. It was seen that the sample showing saturable absorber to reverse saturable absorber at 532 nm wavelength at incident optical beam peak intensity (I 0) of 1.53 GW/cm2. Thus the crystal could be a potential candidate of optical switching application. It was also seen that the material possess positive nonlinearity. It was also found that the values of nonlinear absorption coefficient (β) and nonlinear refraction (n 2) increase with increase of excitation intensity irrespective of excitation wavelengths. [ABSTRACT FROM AUTHOR]

Third order nonlinear optical properties of organic crystal L-threoninium P-toluenesulfonate monohydrate was investigated by 'Z-scan' technique employing two different laser sources under different intensities at 532 nm CW laser and 1064 nm pulsed laser respectively. Nonlinear absorption coefficient (α NL) and nonlinear refraction (n 2) were evaluated at six different intensities using 532 nm CW laser source and with pulsed laser source (λ = 1064 nm) by changing the pulse rate keeping intensity same. It is found that this crystal possesses positive nonlinearity and exhibit saturation absorption. • NLA coefficient (β) and NLR (n 2) of L-threoninium P-toluenesulfonate monohydrate organic single crystal using two laser sources at 532 nm and 1064 nm. • It is found that this crystal possess positive nonlinearity and exhibit saturation absorption. • The nonlinear absorption of this crystal found to be negative. • This crystal may be useful in optical switching application. [ABSTRACT FROM AUTHOR]