Nonlinear optical response of germanium nanoparticles

作者：Kumar Manoj; Shukla A K^*; Mavi H S; Vankar V D

来源：Journal of Optics A: Pure and Applied Optics , 2008, 10(8): 085103.

DOI：10.1088/1464-4258/10/8/085103

• self-phase modulation
• PL spectroscopy
• refractive index

Nonlinear changes of the refractive index are observed by electromagnetic interaction of laser light with germanium nanoparticles. Self-phase modulated optical fringes are used to reveal the nonlinear optical response of germanium nanoparticles at the wavelength of 514.5 nm. The intensity dependence (photo-induced) and size dependence of the refractive index are studied using self-phase modulation of the laser beam. The optical fringe patterns, which are observed due to photo-induced refractive indices, are found to depend on the size of the nanoparticle. The Drude model is also utilized to explore the origin of the photo-induced refractive index of the germanium nanoparticles. It is found that photo-excited electrons contribute appreciably to the nonlinear changes of the refractive index.

• 出版日期2008-8