Optical Bistability of Spin Coated Poly(3-octylthiophene)/Polymethylmethacrylate Composite Waveguides

Abstract

Poly(3-octylthiophene)/polymethylmethacrylate (P3OT/PMMA) composite thin films were prepared by spin coating as composing a prism-coupling waveguide. The optical absorption property of the composite thin film was evaluated using UV-visible spectra in the range 300-900 nm. The optical bistable characteristics of the prism-coupling waveguide composed of P3OT/PMMA composite film was measured for different input laser power intensities using optical bistable measuring equipment. The optical bistability of the waveguide was measured using a Nd:YAG laser with a wavelength of 1,064 nm, pulse width of 5 ns and a repetition frequency of 10 Hz. The optical bistable characteristics of P3OT/PMMA composite waveguides for different input power intensities shows good stability and hysteresis characteristics. However, in terms of the input laser power dependence of optical bistability, the switching on-off position shifts with the increase in input power intensity. In addition, the effect of organic gas treatment and PMMA molecular weight on the optical bistable characteristics of P3OT/PMMA composite waveguides was investigated.