Abstract
To support low-cost and user-friendly internet environments for widespread use, telecommunications networks must operate flexibly at high speed and with a wide bandwidth. Photonic network technology based on wavelength division multiplexing (WDM) systems is essential for this purpose, and the development of new optical devices is thus an important requirement. Recently, various optical devices composed of high-density planar lightwave circuits (PLCs) have been developed for photonic network applications. This paper reports recent progress on large-scale and highly functional PLC-type devices, including arrayed-waveguide grating filters, optical switches and adaptive filters.
