The rhodamine B-doped polymer optical planar waveguide with low propagation loss of 0.44 dB/cm has been fabricated and measured by using scanning near-field optical microscopy and m-line method. The mode structure, near-field topography and near-field fluorescence are obtained, respectively. This may have potential applications in the study of polymer waveguide laser and amplifier.
The polarized emission behaviors of the Eu3+ doped azo-polymer waveguide were reported in this paper. Affected by the azobenzene groups in the photoinduced orientation process by the 532nm linearly polarized laser, the ligands were realigned orderly perpendicular to the direction of the orientation direction. This leads to the polarized absorption and emission of the waveguide in the orientation direction. By an m-line apparatus based on the prism coupling technique, two guided modes propagation were observed in the waveguide at 650nm in TE polarizations.
Azobenzene polymers show large optical anisotropy, and one can control the optical anisotropy by changing the alignment of the molecules with light. Azo groups fall perpendicularly to the direction of the electric field vector of the linear polarized light by photoisomerization. This reorientation induces anisotropy and the difference of refractive index parallel and perpendicular to the irradiating laser polarization direction. In this paper, the photoinduced birefringence induced with 532 nm light in films of azobenzene polymer has been studied as a function of temperature, light intensity. From the evolution of the birefringence induced by laser, the temperature effects on photochemical trans-cis-trans isomerization cycles have been probed and analyzed. The effect of laser-induced heating has been introduced to the buildup of photoinduced birefringence in azobenzene-side-chain copolymer. The curves for the buildup of birefringence were fitted with a modified function, namely, biexponential curves and Gaussian curves. The relationship of each parameter has been also presented. With the modified fitting function, we obtained better fitting result.
We report the near-field investigation on azobenzene contained polymer films using scanning near-field optical microscopy. Nanometer scale dots and lines were inscribed on these films, and the topographies and transmitting images of these patterns could be obtained at the same time. The transmitting images were in agreements with the topographies, and it proved that trans-cis isomerization of the azobenzene moieties in the illuminated area induced both surface relief and anisotropy. The experimental results helped to discover the mechanism of the photo induced surface relief and anisotropy, and the agreement between the transmitting images and the topographies could be applied in pure optical writing/reading in high-density data storage.