Thermo-optic switch using fluorinated silicon oxide and organic spin-on-glass films

A thermo-optic switch in a thin-film optical waveguide was investigated. Fl uorinated silicon oxide (SiOF) and organic spin-on-glass (SOG) films were u sed as core-layer and clad-layer, respectively, in the waveguide structure. The SiOF films were formed at 23 degreesC by a liquid-phase deposition (LP D) technique using a supersaturated hydrofluosilicic acid (H2SiF6) aqueous solution. Thermal coefficients of the refractive indices for LPD-SiOF and o rganic SOG films formed on silicon (Si) substrates were -4.0 x 10(-6)/degre esC, -60 x 10(-6)/degreesC at the wavelength of 632.8 nm, respectively. A h igh extinction ratio of 15 dB was obtained for this switch at the applied v oltage of 12.8 V.