Dynamic coupler using two-mode optical waveguides

摘要

An optical mode coupling apparatus includes an optical waveguide that couples an optical signal from one propagation mode of the waveguide to a second propagation mode of the waveguide. The optical signal propagating in the waveguide has a beat length, and the coupling apparatus includes a source of perturbational light signal that propagates in the waveguide in two spatial propagation modes having different propagation constants so as to have a perturbational signal beat length. The perturbational signal has an intensity distribution in the waveguide that causes periodic perturbations in the refractive indices of the waveguide in accordance with the perturbational signal beat length. The periodic perturbations of the refractive indices of the optical waveguide cause cumulative coupling of the optical signal from one propagation mode to another propagation mode. The perturbational light signal can be selectively enabled and disabled to selectively enable and disable coupling of the optical signal between the propagation modes.