Laser Laboratory, Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Jul;93:135-9. doi: 10.1016/j.saa.2012.02.093. Epub 2012 Mar 3.
The present work focuses on the nonlinear optical behavior of chalcogenide As(2)S(3) film as well as on bulk material. The thin film of As(2)S(3) grown by thermal evaporation and bulk glass developed by melt-quenched technique has been characterized using nanosecond pulses of Nd:YAG (532 nm) and Nd:YVO(4) (1,064 nm) laser. Using Z-scan technique, the laser induced nonlinear optical parameters viz. nonlinear refractive index (n(2)), nonlinear absorption coefficient (β) and third order nonlinear susceptibility (χ(3)) have been estimated. At 1,064 nm excitation, the materials exhibit stronger nonlinearity as compared to that of 532 nm laser. In case of As(2)S(3) thin film, observed nonlinearity attributes to two-photon absorption. The optical limiting response of chalcogenide film as well as bulk sample has also been reported. The study predicts that the As(2)S(3) thin film is a better optical limiting material than bulk glass due to relatively higher nonlinearity and lower limiting threshold.
本工作主要研究了硫属化物 As(2)S(3)薄膜及块状材料的非线性光学行为。采用热蒸发法生长的 As(2)S(3)薄膜和熔融淬冷技术制备的块状玻璃，利用纳秒脉冲 Nd:YAG(532nm)和 Nd:YVO(4)(1064nm)激光进行了表征。采用 Z 扫描技术，估算了激光诱导的非线性光学参数，如非线性折射率(n(2))、非线性吸收系数(β)和三阶非线性极化率(χ(3))。在 1064nm 激发下，与 532nm 激光相比，材料表现出更强的非线性。对于 As(2)S(3)薄膜，观察到的非线性归因于双光子吸收。还报道了硫属化物薄膜和块状样品的光限幅响应。研究表明，由于相对较高的非线性和较低的限幅阈值，As(2)S(3)薄膜是一种比块状玻璃更好的光限幅材料。
