Fabrication of Mach-Zehnder polimer waveguides by a direct-drawing technique using a focused proton beam

Miura, Kenta*; Sato, Takahiro; Ishii, Yasuyuki; Kiryu, Hiromu*; Ozawa, Yusuke*; Koka, Masashi; Takano, Katsuyoshi*; Okubo, Takeru; Yamazaki, Akiyoshi; Kada, Wataru; Yokoyama, Akihito; Kamiya, Tomihiro; Hanaizumi, Osamu*

We develop a thermo-optic switch of the Mach-Zehnder type polymer waveguide using proton beam writing (PBW). In this study, we succeeded in near field pattern Mach-Zehnder type single mode polymer waveguides at a wavelength of 1550 nm. The samples for the waveguides were composed with a 15--thick under-cladding layer of SiO deposited on a Si substrate using radio-frequency sputtering and a 10-m-thick PMMA film spin-coated onto the SiO layer as a core layer. We wrote Mach-Zehnder type waveguides having a width of 8 m on the PMMA layer by PBW with a beam size of 1 m and a beam current of 50 pA. After this writing, the 10-m-thick-PMMA layer was deposited again as an upper-cladding layer by spin-coating. In the observation of these waveguides, the light of laser of 1550-nm wavelength was injected into one side of the waveguide through a single-mode fiber. From the observation of the light emitted from the opposite side of the waveguides, near field patterns was observed using a vidicon camera with an optical microscope. The observation result demonstrated that the light traveled by single mode in the Mach-Zehnder type polymer waveguide. In the conference, we will report the development of the Mach-Zehnder type polymer waveguide in detail. In addition, the thermo-optic switch at the wavelength of 1550 nm by the Mach-Zehnder type polymer waveguide will also be briefly reported.