Tunable optical filter
AssigneeTelefonaktiebolaget LM Ericsson
InventorJean-Pierre Weber
Life of this patent
Estimating the term…
Abstract
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.
Claims24
A tunable optical filter, comprising:
- a first semiconductor substrate having a first electrode means provided on a first surface thereof;
- a waveguide means formed in and laterally defined within the surface of said substrate for carrying light waves;
- a plurality of tunable reflection grating means provided on a second surface of said semiconductor substrate on top of said waveguide, wherein said reflection grating blocks incoming lightwaves when said grating is untuned;
- an insulating substrate means provided on both sides of said waveguide;
- and
- a plurality of electrode means, wherein each of said tunable reflection gratings has an electrode for varying an effective index of refraction of a section of said waveguide below said grating.
A tunable optical filter for a communication system with a plurality of channels, comprising:
- a first semiconductor substrate having a first electrode means provided on a first surface thereof;
- a waveguide means formed in and laterally defined within the surface of said substrate for carrying light waves;
- a plurality of tunable reflection gratings means provided on a second surface of said semiconductor substrate on top of said waveguide, wherein each of said tunable reflection gratings blocks a particular channel of the communication system;
- an insulating substrate means provided on both sides of said waveguides;
- and
- a plurality of electrode means for varying the effective index of refraction of a section of said waveguide below said grating.
A tunable optical filter, comprising:
- a substrate;
- a dielectric cladding layer provided on top of said substrate;
- a waveguide means formed in and laterally defined within the surface of said cladding layer;
- a plurality of tunable reflection grating means provided on top of said waveguide, wherein said reflection grating blocks incoming lightwaves when said grating is untuned;
- and
- a plurality of heating elements on top of said cladding layer, wherein each of said tunable reflection gratings has a heating element for varying an effective index of refraction of a section of said waveguide below said grating.
Dependencies are inferred from the claim text.