Optical Bistability of Poly(3-octylthiophene)/Polymethylmethacrylate Composite Waveguides Prepared by Spin Coating

Abstract

Poly(3-octylthiophene)/Polymethylmethacrylate (P3OT/PMMA) composite waveguides were prepared by spin coating method as composing a prism-coupling waveguide. The UV-vis spectrum of P3OT/PMMA thin film was recorded in the range 300-900 nm using spectrophotometer to determine the optical absorption property of the composite thin film. The prepared P3OT/PMMA waveguide was treated with organic gas for 25 hrs to smoothing the surface of the thin film. An Nd: YAG laser with a wavelength of 1064 nm, a pulse width of 5 ns and a repetition frequency of 10 Hz was used for optical bistability measurement. The optical bistable characteristics of prism coupling waveguide comprising with P3OT/PMMA composite thin film was measured for different laser power intensities using optical bistable measuring equipment. The measured optical bistability displaced good stability and hysteresis characteristics. The input power dependence of optical bistability was observed and the switching on-off position shifted with the increase of input power intensity. In addition, the effects of organic gas treatment on the optical bistability of P3OT/PMMA composite waveguides were analyzed.