Heat-resistant flexible-film optical waveguides were fabricated from fluorinated polyimides. These waveguides operated in single mode and had low optical loss (0.3 dB/cm) at a wavelength of 1.3 μm for TE and TM polarizations. They also had good flexibility: The optical loss did not significantly change above a minimum radius of curvature of less than 20 mm. The birefringence of 9 × 10<sup>−5</sup> between the TE and TM polarizations is 2 orders of magnitude smaller than that for a waveguide upon a substrate. Moreover, these waveguides had high thermal stability and moisture resistance: The optical loss and single-mode behavior changed little after heating the waveguides at 420 °C for 1 h or after their exposure to 85% relative humidity at 85 °C for more than 350 h.
© 1999 Optical Society of America
Tohru Matsuura, Junya Kobayashi, Shinji Ando, Tohru Maruno, Shigekuni Sasaki, and Fumio Yamamoto, "Heat-Resistant Flexible-Film Optical Waveguides from Fluorinated Polyimides," Appl. Opt. 38, 966-971 (1999)