We present research on nonether polyphenylquinoxaline film waveguides, and a scheme for an all-opticalswitching operation of waveguides is suggested. We use the m-line spectroscopy technique to characterize theguiding modes in the waveguide, and the switching phenomenon is observed with two-wavelength nonlinearprism coupling. The measured response time of the switching signal is less than 10 -9s.

We report theory and experiment on ultrahigh-order modes in a symmetrical metal-cladding thickoptical waveguide. The waveguide consists of a LiNbO3 slab or a glass slab with a thickness greaterthan 0.1mm, two gold films deposited on the upper and bottom sides of the slab serving as thecladding of the waveguide. By using the free-space coupling technique, ultrahigh-order modes m 2000 are excited, and its high sensitivity to both refractive index and thickness of the guide,as well as the polarization independence are demonstrated.

An oscillating wave sensor based on Fabry-Perot resonance modes has been developed. Different fromthe surface plasmon resonance sensors and the waveguide mode sensors in which the sample is locatedin the evanescent field region, the proposed device contains the sample in the core region that supportsthe oscillating field. Owing to the strong concentration of the electromagnetic field in the sensingmedium, the proposed device exhibits unusual sensitivity enhancement, which has never been exploitedin any other devices.

A new technique for measuring the electro-optic coefficient of nonlinear optical polymer is described. In anattenuated-total-reflection experiment the refractive index of the poled polymer is changed because of thePockels effect. This change causes a shift of the angular position of the surface plasmon modes that correspondsto a change in reflectivity at a fixed angle. By measuring the change of the light reflectivity at theproperly chosen angle one can calculate the electro-optic coefficient of the poled polymer. Compared withother, conventional methods, here the electro-optic coefficients are given in a simpler form and the requiredparameters are easier to measure. The commonly used lock-in amplifier is not required. This technique is ahighly sensitive method for measuring the electro-optic coefficient because of the newly chosen working interiorangle for which a tiny change in the refractive index leads to a large change in reflectivity.

We present a novel matrix approach to proving that the phase shift at a turning point in a planar optical waveguideis exactly equal to π rather than to π/2 or to some other value. We also show the existence of phasecontributions from reflected subwaves, which to our knowledge have never been taken into account previously.