High performance planar lightwave circuit devices for large capacity transmission.

Both high-density multiplexing and high-speed transmission are required for large capacity networks supporting broadband service penetration. Silica waveguide optical circuit technology can provide key optical devices for such systems because it has high controllability as regards optical amplitude and sufficient phase for realizing sophisticated optical interferometric circuits. This paper reviews recent progress on this technology, and reports experimental results for an ultra wideband AWG, an optical OFDM filter, a demodulator for a coherent receiver and a highly functional modulator.