Polarization-independent electrically tunable narrowband optical filters

Narrowband optical filters based on the principle of phase-matched, but nonidentical, coupled waveguides can provide for ready integration to semiconductor photonic circuits and easy electronic tuning. By increasing the asymmetry and/or reducing the coupling strength between the waveguides, the filter bandwidth can be reduced. In this work it is shown, through rigorous numerical simulations, that a design incorporating a multiple quantum well core can be used to compensate the undesirable polarization effects otherwise seen. Numerically simulated results are presented for polarization-independent narrowband electrically-tuned optical filters with two-dimensional confinement