Polymer 1×2 Thermo‐Optic Digital Optical Switch Based on the Total‐Internal‐Reflection Effect

This letter presents a polymer 1×2 thermo‐optic total‐internal‐reflection digital optical switch (TIR‐DOS) with an index contrast of 1.5%‐Δ operating at low power consumption. The structure of our 1×2 TIR‐DOS was created by adding a reflection port to that of a conventional multimode filtering variable optical attenuator. To improve the total‐internal‐reflection efficiency, a heater offset was applied to the crossing region of multimode waveguides of the TIR‐DOS. The fabricated 1×2 TIR‐DOS shows a low electrical power consumption of 18 mW for an on‐off ratio of 35 dB.