OPTICAL POLYMER WAVEGUIDE WITH TUNABLE POLARIZATION MODE DISPERSION

In the last years optical polymer waveguides have attracted great inter-est as easy-to-make and robust elements of various optical devices. The refractive index anisotropy of waveguide modes and the mechanical stress generated in polymer materials during the process of waveguide fabrication lead to a polarization mode dispersion, which limits their practical applications. One possibility to compensate this effect is a defined induced optical anisotropy in the waveguide. In the present work we have investigated slab waveguides made of an original benzaldehyde-containing polymer with a high refractive index demonstrating the photoinduced birefringence. The birefringence of the material arises under polarized ultraviolet irradiation and is characterized by good thermal and optical stability. The effect of the photoinduced birefringence on the polarization properties of a laser beam carrying TE0 and TM0 modes with regard to their simultaneous and separate excitation has been investigated experimentally. The possibility to control the dispersion of the modes by varying the value of birefringence has been demonstrated.