| 摘要 |
<p>A diffraction grating of non-uniform strength is introduced into an optical waveguide (42) by modulating its width. The waveguide may be fabricated using one of several planar processing techniques. Varying the size, position, and/or thickness of the grating teeth (44) provides the desired variation of grating strength. Certain functional variations of grating strength suppress side-lobe levels in the grating reflection and transmission spectra. This process, termed apodization, is necessary for precise wavelength filtering and dispersion compensation. If desired, different periodicity gratings can be introduced in each side of the waveguide, multiple periodicities can be superimposed, the grating can be angled with respect to the waveguide, and the grating period and phase can be varied.</p> |
