Lattice-form CWDM interleave filter using silica-based planar lightwave circuit

We demonstrate an eight-channel coarse wavelength-division-multiplexing interleave filter that employs a silica-based lattice-form filter. The filter incorporates phase-generating couplers to convert a conventional frequency interleave filter into a wavelength interleave filter with a constant channel spacing with respect to wavelength. We fabricated the designed interleave filter on a 1.5%-Delta silica-based waveguide and realized a constant channel spacing of 20 nm with a wavelength displacement of within plusmn0.5 nm and an insertion loss of less than 1.7 dB over eight channels