| Tunable optical filter - US 5459799 A |
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| 2016-02-02 |
| A tunable optical filter for use in wavelength division multiplexing systems. The optical filter contains a plurality of tunable reflection gratings which block all of the channels in the incoming lightwave. An electrode or a heating element is provided for each reflection grating to tune the reflection gratings so that their reflection bands do not coincide with a desired channel or channels thereby allowing the desired channel or channels to pass through the filter. |
