Optical push broom in a silicon waveguide

Abstract

We report on light trapping by a moving refractive index front inside a silicon waveguide, the so-called optical push broom effect. The front generated by a fast pump pulse collects and traps the energy of a signal wave with smaller group velocity tuned near to the band gap of the waveguide with hyperbolic dispersion. The energy of the signal wave is accumulated inside the front and distributed in frequency. The presented effect can be utilized to compress signals in time and space.