| 摘要 |
<p>An optical filter comprises a multi-mode waveguide (W2) and a single-mode waveguide (W1, W3) coupled in series, the interference of different modes at the multiple-mode/single-mode interface being effective to filter an optical signal propagating through the waveguides to provide a desired wavelength response characteristic. The offset between the waveguides may be varied to control the filter characteristic. The filter may be formed in the cavity of a laser to produce an output having a comb-filter characteristic. It may be used as channel selector in WDM systems.</p> |
