Active optical switches based on polarization-tuned guided-mode resonance filters for optical communication

An active optical switch based on polarization-tuned guided-mode resonance filter (GMRF) for the optical communication wave band is experimentally demonstrated. The proposed active optical switch consists of a linear polarizer, a twisted nematic liquid crystal (TN-LC) polarization rotator and a GMRF from top to bottom. Two fabricated optical switches exhibit high resonance peaks with wavelengths around 1310 and 1550 nm in the voltage-off status. In the voltage-on status, weak light signals without resonance peaks pass through the optical switches. Thus light signal can be tuned by controlling the applied voltage on the TN-LC of the optical switch.