Mode quasi-degeneracy and beam reflection in the total-internal-reflection optical waveguide switch

摘要

We investigate the beam reflection mechanism in a bounded space, which is applied in the practical total-internal-reflection (TIR) optical waveguide switch. Due to the confinement of the waveguide, the beam reflection within the TIR switch is completely different from that in free space. Its essence is the quasi-degeneracy between the even and the odd modes in the reflection region. Since different modes require different refractive index decreases to reach the quasi-degenerate state, we reduce the electrode power by controlling the mode excitation in the reflection region. Several guidelines are proposed for designing the TIR switch. (C) 2008 Optical Society of America