Nested spiral chirped waveguide Bragg gratings for tunable dispersion compensation

A novel low-loss on-chip optical dispersion compensator based on nested spiral chirped waveguide Bragg gratings is proposed. As a proof-of-concept demonstration, the device achieves 3-nm bandwidth, 1.75-dB loss, and dispersion compensation up to 7.5-km SMF with low group delay ripple less than ±3 ps.