A compact and monolithic four-channel demultiplexer with 20-nm spacing was fabricated by use of a high-spatial-frequency transmission grating buried in a silica waveguide. The grating was successfully buried in a silica slab waveguide by overcladding by plasma-enhanced chemical-vapor deposition. The device’s size was approximately 5.1mm×9.2mm . The average insertion loss was 13 dB. The average cross talk was -15dB for adjacent channels and -19dB for nonadjacent channels. The polarization-dependent loss was estimated to be as low as 0.7 dB.
© 2004 Optical Society of America
Tatsuhiro Nakazawa, Shigeo Kittaka, Keiji Tsunetomo, Kenji Kintaka, Junji Nishii, and Kazuyuki Hirao, "Compact and monolithic coarse wavelength-division multiplexer-demultiplexer fabricated by use of a high-spatial-frequency transmission grating buried in a slab waveguide," Opt. Lett. 29, 1188-1190 (2004)