Ultra-compact and low-loss silica-based dual polarization optical hybrid for digital coherent receiver with excellent common-mode rejection ratio

An ultra-compact 3 × 12 mm
²
DPOH on a 1.5%-Δ silica-based PLC employing a novel coupler is reported. The excess loss is <;2 dB and the CMRR is <;-27 dBe over the C- and L-bands.