An optical variable attenuator for DWDM system applications has been developed by Santec Corp. The OVA-650 has a neutral density filter for performance over both the C- and L-bands. It has an insertion loss of <0.6 dB and is supplied with either 15- or 30-dB configurations. The unit features low polarization dependence of <0.15 dB, low temperature dependence and low wavelength dependence. It is hermetically sealed and qualified to Telcordia GR-1221 standards and is suitable for use in transmitter or receiver power control and EDFA gain control.