Liquid-crystal WDM power equalizer

Abstract

In this work, we demonstrated a liquid-crystal WDM (wavelength-division-multiplexing) power equalizer. It provides functionality of optical power equalization and tilting using liquid-crystal modulators and harmonic synthesis approach. The demonstrations show fast gain equalization within a flatness of ±0.3dB for several optical amplifier profiles in C or L bands. The equalization for WDM discrete-channel cases also reached flatness within ±0.3dB. The measured polarization dependent losses are less than 0.15dB and 0.1dB for flattened and through-state profiles, respectively. The measured polarization mode dispersions are less than 0.15ps under the through, flattened and 10-dB attenuation states. The measured chromatic dispersion is less than°7ps/nm.