Isamu TAKISHITA^1,2, Kenji KUROSU^3*, and Tetsuya HOMMA⁴

¹Division of Functional Control Systems, Graduate School of Engineering (Doctors Program), Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548, Japan
²Sumitomo Densetsu Corporation Limited, 4-5-12 Mita, Minato-ku, Tokyo 108-8303, Japan
³Division of Electrical Engineering and Computer Science, Graduate School of Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548, Japan
⁴Department of Electronic Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548, Japan

(Received July 3, 2007; Accepted July 7, 2008)

Optical switching devices have been studied using thin-film optical waveguides with fluorinated silicon oxide (SiOF) films deposited by a liquid-phase deposition (LPD) technique. This report focuses on the structure of the thermo-optical (TO) switch and its optimization. TO devices with double- and triple-layer structures were fabricated using a material with an organic spin-on-glass (SOG) cladding layer and a liquid-phase deposited (LPD) SiOF core layer. The maximum extinction ratio of 15.97 dB was obtained for the double-layer structure TO devices at the half-wavelength power of 2.78 W, and at the heater area of 0.02 mm². The response time decreased with decrease in the heater area for both double- and triple-layer structures. The response time as short as 6.3 ms was obtained at the heater area of 0.02 mm² for the double-layer structure. For the triple-layer structure, an even shorter response time of 2 ms was achieved at the heater area of 0.08 mm², and this was over one order of magnitude smaller than that for the double-layer structure at the same heater area (280 ms).

Key words: thin-film optical waveguide, thermo-optical switch, liquid-phase deposition, SiOF film, spin-on-glass

^*Present address: Panasonic Communications Co., Ltd., 2-8-3 Shimo-Meguro, Meguro-ku, Tokyo 153-8687, Japan.