Enhanced optical modulation using azo-dye polymers

The performance of the conventional azo-dye polymer modulation system is compared with that of the recently developed attenuated-total-reflection (ATR) dye-polymer modulation techniques. Experiments based on Fabry-Perot resonance shifting in ATR geometry indicate that the modulation parameters, namely, speed, contrast, and efficiency, are enhanced. Although the dye-polymer response still remains fairly slow, ATR methods provide substantial improvement over the existing system. An all-optic long-range surface-plasmon azo-dye polymer modulation system is also proposed. Computer simulation of the reflectance and the photoinduced resonance shifting suggest that the proposed system can be used effectively for all-optic modulation. Some of the limitations of both systems and a pratical application of the ATR modulation methods are discussed.