The Influence of Quantum Confinement on Third-Order Nonlinearities in Porous Silicon Thin Films

Applied Sciences

LeighT. Canham¹  Jack Collins¹  Rihan Wu¹  Andrey Kaplan¹ 

[1] School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK;

关键词: third-order nonlinearity;    self-focusing;    TPA;    porous silicon;    Z-scan;   

DOI  :  10.3390/app8101810

来源: DOAJ

【 摘 要 】

We present an experimental investigation into the third-order nonlinearity of conventional crystalline (c-Si) and porous (p-Si) silicon with Z-scan technique at 800-nm and 2.4- μ m wavelengths. The Gaussian decomposition method is applied to extract the nonlinear refractive index, n 2, and the two-photon absorption (TPA) coefficient,β , from the experimental results. The nonlinear refractive index obtained for c-Si is 7 ± 2 ×10− 6 cm 2/GW and for p-Si is − 9 ± 3 ×10− 5 cm 2/GW. The TPA coefficient was found to be 2.9 ± 0.9 cm/GW and 1.0 ± 0.3 cm/GW for c-Si and p-Si, respectively. We show an enhancement of the nonlinear refraction and a suppression of TPA in p-Si in comparison to c-Si, and the enhancement gets stronger as the wavelength increases.

【 授权许可】

Unknown