Manipulating photons in a way like an optical tweezer

Abstract

Arbitrary control of photon flow is of fundamental significance in many applications of light. Here, we propose a new approach that can trap, store, and move the signal photons to arbitrary desired place, just like what optical tweezers do on micro particles. In addition, the trapped photons can also be released at a given direction. The mechanism is based on an ultrahigh-Q nanocavity formed by two dynamically-generated potential barriers in a photonic crystal (PC) waveguide. Different from the traditional fixed ultrahigh-Q nanocavities, this new-type cavity can be formed instantaneously at any moment and any position in a PC waveguide, and is completely movable while keeps ultrahigh Q factor simultaneously. These novel features make controlling the flow of light like an optical tweezer possible, and open up new opportunities for dynamic light–matter interactions and on-chip optical signal processing.