Experimental demonstration of photonic bandgaps in azopolymer resonant waveguide grating systems

Photonic bandgaps are demonstrated in one-dimensional corrugated waveguides in the infrared range. A coupling grating is superimposed with single and double Bragg gratings on an azopolymer film by a simple optical process, which allows easy control of the grating spacing. Light is coupled to the TE(0) resonant mode, and gaps in the dispersion curve are introduced by careful selection of the gratings. The analysis is carried out by measuring the transmission through the waveguide as a function of the wavelength and angle of incidence of a probe beam. This results in a direct measurement of the dispersion curves, which are in excellent agreement with theory.