10 GHz-spaced arrayed-waveguide grating multiplexerwith phase-error-compensating thin-film heaters

Abstract
An arrayed-waveguide grating multiplexer with thin-film heaters is fabricated to compensate for phase errors in arrayed waveguides. The phase errors are measured by Fourier transform spectroscopy with a low-coherence interferometer and are used as a monitor when we adjust the phases by controlling thin-film heaters. A channel crosstalk of –25 dB and a loss of 4.2 dB are achieved in a 5×5 10 GHz-spaced multiplexer.