Silica Nanofiber-Based Evanescent Optical Kerr Effect in Nonlinear Liquid Media

Tapered optical fibers with ultra-small radii provide an intriguing platform for confining light, leading to the generation of nonlinear effects and the formation of an intense evanescent field that effectively interacts with the surrounding medium. In this paper, we give a theoretical demonstration of the evanescent field's major contribution to the Kerr effect observed in a silica nanofiber surrounded by liquids at a wavelength of 780 nm, including water, ethanol, and acetone. Our findings reveal an evanescent Kerr effect that outperforms the traditional Kerr effect within the nanofiber core when the nanofiber diameter is less than 0.793 particularly in the presence of acetone. As a result, these nanofibers exhibit exceptional promise as sensors for scrutinizing external media, particularly in hard-to-reach locations, by harnessing the potential of the evanescent optical Kerr effect.