摘要 |
<p>A guided-mode resonance filter is provided which can be used as an optical filter with very narrow line width and as an efficient optical switch. Diffraction efficiencies and passband frequencies are calculated based on guided-mode resonance properties of periodic dielectric structures in a waveguide geometry. The guided-mode resonance filter preferably includes means for changing various parameters within the grating (10) so as to change passband frequencies in response thereto. Also, the present invention envisions a narrowband tuneable laser having a diffraction grating of the present invention placed within a laser cavity to provide narrowband optical wave output from the narrowband tuneable laser. In another preferred embodiment, the present diffraction grating can be supported by a semiconductor substrate, preferably adjacent to a semiconductor laser for fine-tuning the output of the semiconductor laser. In still another preferred embodiment, the present diffraction grating can be placed between thin-film layers to enhance thin-film performance characteristics.</p> |