We have developed a thin-film optical waveguide, which is capable of condensing light at an input terminal of the waveguide.　 The waveguides are composed of under-cladding, core, and over-cladding layers. All of them have been made of fluorinated polyimides. The lens effect of the waveguide improved the resolution.

References :

Tetsuo Kan, Kiyoshi Matsumoto, Isao Shimoyama, “Thin-Film Waveguide with a Lens Effect Terminal for Optical Sensing Devices,” 16th IEEE International Micro Electro Mechanical Systems Conference (MEMS '03), pp. 315-318, Kyoto, Japan, Jan. 19-23, 2003. [Proceedings]