Packaged polarization-insensitive WDM monitor with low loss (7.3 dB) and wide tuning range (4.5 nm)

Low-cost high-performance wavelength-division-multiplexing (WDM) monitors and receivers are key components in WDM transmission and local area optical networks. A semiconductor arrayed waveguide grating integrated with a photodiode is attractive because of its small size and simple fabrication process. A low-loss (7.3 dB) polarization-insensitive packaged WDM monitor has been fabricated in an industry-standard butterfly-type module. The eight-channel monitors, which have 200-GHz channel spacing, can be tuned simultaneously in the 4.5-nm range.