16-channel optical add/drop multiplexer consistingof arrayed-waveguide gratings and double-gate switches

Abstract
An optical add/drop multiplexer that enables full access to 16 individual wavelength channels has been fabricated on the planar lightwave circuit (PLC). The device consists of four arrayed-waveguide gratings which are connected through 16 double-gate thermo-optic switches. The crosstalk characteristics of the optical switches have been improved by adopting a double-gate configuration. The on-off crosstalks from main input or add port to main output or drop port are less than –28.4 dB and the on-chip insertion losses are 7.8–10.3 dB, respectively.