Automatic Wavelength Channel-by-Channel Equalizer

We demonstrate a wavelength equalizer in planar silica waveguides that can automatically control individual channel powers in a 40-channel, 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.