| Institution: | (1) Micro-Human-Tech Research and Development Division, Citizen Watch Co., Ltd., 840, Shimotomi, Tokorozawa, Saitama 359-8511, Japan;(2) Optical Design Department, Sagamihara Plant, Nikon Corp., 1-10-1, Asamizodai, Sagamihara, Kanagawa 228-0828, Japan;(3) Customized Products Division, Nikon Corp., 1-6-3, Nishi-ohi, Shinagawa-ku, Tokyo 140-8601, Japan;(4) Liquid Crystal Display Device Division, Citizen Watch Co., Ltd., 6-1-12, Tanashicho, Nishi-Tokyo, Tokyo 188-8511, Japan |
| Abstract: | We apply liquid crystal on silicon (LCOS) in 0.8-$mUm standard complementary metal-oxide semiconductor (CMOS) technology to demonstrate a low-cost, high-performance pixelized liquid crystal variable optical attenuator (VOA) with pulse width modulation. We then build a prototype tunable filter by using this VOA along with a grating in the Littrow configuration. With the application of 5-V pulse width modulation, the proposed VOA achieves a 5.6-dB insertion loss, a dynamic range of more than 20 dB, a 50-GHz channel spacing capability, and a polarization-dependent loss (PDL) of less than 0.6 dB at 15-dB attenuation. Our VOA is suitable for applications such as dynamic channel gain equalizers, channel-blocking filters, sub-components of re-configurable add-drop modules, and wavelength selectors. |
