Journal article
Ultracompact photonic-waveguide circuits in Si-pillar photonic-crystal structures for integrated nanophotonic switches
Nano Electronics Research Laboratories, NEC Corporation, 34, Miyukigaoka, Tsukuba, Ibaraki 305-8501, Japan.1
Highly integrated optical device technology based on square-lattice Si-pillar photonic-crystal-(PC) waveguides is described. The Si-pillar PC waveguides are now ready to use, since efficient optical coupling structures to Si-wire waveguides have been devised. Nanophotonic switches using the Si-pillar-PC waveguides were experimentally demonstrated.
The nanophotonic switches make use of two of the features of Si-pillar photonic crystal waveguides. One is the property of slow-light and the other is the usability of zero-radius 90 degrees bends, both of which enable waveguide-based optical devices to be greatly miniaturized. Even apart from the cut-off wavelength, the group index of the pillar-PC waveguides was about 7.8, which was about twice that of a Si-wire waveguide for the entire C-band of telecommunications wavelengths.
The 3-dB couplers we fabricated were only 3.2-microm long thanks to the 90 degrees sharp bends, and they operated throughout the entire C-band. Waveguide-cross operation was also demonstrated in the entire C-band. Asymmetric Mach-Zehnder interferometers (MZIs) were configured by using the 3-dB couplers in an area of 13.2 x 37.2 microm.
An MZI with a Si-wire heater successfully operated with an extinction ratio of about 20 dB at a heating power of 17 mW. It is strongly suggested that Si-pillar PC photonic-waveguide technology should help us to achieve densely integrated optical-matrix switches demanded for future photonic-telecommunication systems.
Language: | English |
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Year: | 2010 |
Pages: | 1626-1634 |
ISSN: | 15334899 and 15334880 |
Types: | Journal article |
DOI: | 10.1166/jnn.2010.2046 |