An automatic 40-wavelength channelized equalizer

We demonstrate a wavelength equalizer in planar silica waveguides that can automatically control individual channel powers in a 40-channel 100-GHz-channel-spacing wavelength-division multiplexed system, yet gives no distortion to channels that already have the same power as their neighbors. It has <6.8 dB insertion loss over 32-nm, 9-13-dB attenuation range, and <0.18 dB polarization/time-dependent loss.