Light tunneling inhibition in array of couplers with combined longitudinal modulation of refractive index

TL;DR

This paper demonstrates a method to inhibit light tunneling in optical coupler arrays through combined longitudinal and transverse refractive index modulation, enabling light localization despite differing tunneling rates.

Contribution

It introduces a novel combined modulation scheme that simultaneously suppresses local and global light tunneling in optical coupler arrays.

Findings

Local out-of-phase longitudinal modulation suppresses tunneling within couplers.

Global refractive index modulation inhibits tunneling between couplers.

Light can be localized in a single waveguide despite high tunneling rates.

Abstract

We consider light tunneling inhibition in periodic array of optical couplers due to the specially designed longitudinal and transverse modulation of the refractive index. We show that local out-of-phase longitudinal modulation of refractive index in channels of directional couplers in combination with the global refractive index modulation between adjacent couplers allow simultaneous suppression of both local and global energy tunneling inside each coupler and between adjacent couplers. This enables localization of light in single waveguide despite the remarkable difference of corresponding local and global energy tunneling rates.