WAVE-GUIDE NARROW-BAND OPTICAL FILTER USING SPECTRAL HOLE-BURNING

We have developed a new integrated narrowband spectral filter, which c onsists of a planar waveguide covered with a thin polymer film contain ing molecules, which undergo persistent spectral hole burning at liqui d helium temperature. We show that such a device performs as a miniatu re programmable narrowband spectral filter, with a transmission bandwi dth less than 1 GHz. In such a filter the frequency resolution is limi ted by the width of the homogeneous zero-phonon lines of the chromopho re molecules, and not by the geometrical dimensions of the device. Exp erimental measurements in the time domain using a picosecond dye laser , and in the frequency domain using a single-mode diode laser, are pre sented.