Compact filters and demultiplexers based on long-range air-hole assisted subwavelength waveguides

Compact filters and demultiplexers based on long-range air-hole assisted subwavelength (LR-AHAS) waveguides have been proposed and numerically demonstrated. The tunable reflective filters possess the characters of high extinction ratio (17.5dB) and narrow bandwidth (10.1nm). The average demultiplexing bandwidth of a 1 × 3 wavelength demultiplexer based on LR-AHAS waveguide is 17.3 nm. The drop efficiencies can be significantly enhanced up to 60% by employing proposed filters in the structure. With distinguished wavelength-filtering/dropping characters and compact footprints, the proposed filters and demultiplexers could become the fundamental signal processing components in the LR-AHAS waveguides for large-scale photonic integrations.