Abstract
We show that standard approximations in nonlinear optics are violated for situations involving a small value of the linear refractive index. Consequently, the conventional equation for the intensity-dependent refractive index, , becomes inapplicable in epsilon-near-zero and low-index media, even in the presence of only third-order effects. For the particular case of indium tin oxide, we find that the , , and contributions to refraction eclipse the linear term; thus, the nonlinear response can no longer be interpreted as a perturbation in these materials. Although the response is non-perturbative, we find no evidence that the power series expansion of the material polarization diverges.
© 2017 Optical Society of America
Full Article | PDF ArticleMore Like This
Xu A. Zhang, Yi-An Chen, Abhijeet Bagal, and Chih-Hao Chang
Opt. Lett. 42(20) 4123-4126 (2017)
Taylor K. Fryett, Alan Zhan, and Arka Majumdar
Opt. Lett. 42(18) 3586-3589 (2017)
M. A. Vincenti, D. de Ceglia, and Michael Scalora
Opt. Lett. 41(15) 3611-3614 (2016)