[14p-PB3-1~8] 3.15 Silicon photonics and integrated photonics

[14p-PB3-5] Light-Induced Self-Written Optical Waveguide Fabrication by Near Infrared Continuous Wave Laser Light with Microwatt Power

〇Hidetaka Terasawa¹, Okihiro Sugihara¹ (1.Utsunomiya Univ.)

Keywords:silicon photonics, polymer waveguides, optical interconnection

We have successfully demonstrated light-induced self-written (LISW) waveguides at wavelengths of 1.07μm and 1.31 μm, respectively. We used an acrylate monomer, a radical generator, a co-initiator and a near-infrared (NIR) photosensitive dye. The NIR photosensitive dye shows light absorption in the NIR region that covers wavelength from 0.75 μm to 1.6 μm. We mixed the acrylate monomer, the radical generator, the co-initiator and the NIR photosensitive dye to obtain a NIR photosensitive resin mixture. First, we performed a pre-UV exposure by a UV mercury lamp as a result of an increase in the viscosity of the resin mixture. Therefore, we can avoid bending of the LISW waveguide. After the pre-UV process, we irradiated resin mixture with a NIR continuous wave (CW) laser light, so that a straight polymer optical waveguide was formed. We used CW lasers at wavelengths of 1.07μm and 1.31 μm. The LISW fabrication threshold laser output power was 1 μW and 500 μW at 1070 nm and 1310 nm, respectively. We experimentally confirmed that the microwatt level photopolymerization threshold value was obtained at both wavelengths. We believe that this technique will be useful for interconnection optical devices, especially in the field of silicon photonics.