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US 12,586,985 B2Granted
Distributed feedback laser with complex coupling
AssigneeNokia Solutions and Networks Oy
InventorsAlexandre Garreau, Jean Francois Paret
Life of this patent
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Abstract
A distributed feedback laser (DFB) is a type of laser diode in which the active region of the device contains a periodically structured element or diffraction grating, which may include periodic changes in refractive index that cause reflection back into the laser cavity. Conventional DFB lasers used in optical networks may exploit either loss-modulated or index-modulated gratings. In the case of complex-coupling, index-modulated and loss-modulated gratings may be combined together.
Claims15
A distributed feedback laser comprising:
- an optical waveguide gain medium configured to amplify light at a laser wavelength;
- a first optical grating comprising a first plurality of index-modulated grating structures having a period Λ disposed on one side of the optical waveguide gain medium;
- and
- a second optical grating comprising a second plurality of loss-modulated grating structures having a same period Λ, with an offset of Λ/4±Λ/8 from the first plurality of index-modulated grating structures, disposed on another side of the optical waveguide gain medium, opposite the first optical grating.
1 more element
A method of manufacturing a distributed feedback laser comprising:
- a) providing a substrate;
- b) providing a first optical grating over the substrate comprising a first plurality of grating structures having a period Λ;
- c) providing an optical waveguide gain medium over the first optical grating configured to amplify light at a laser wavelength;
- and
- d) providing a second optical grating over the optical waveguide gain medium comprising a second plurality of grating structures having the period Λ with an offset of Λ/4±Λ/8 from the first plurality of grating structures;
- wherein the first optical grating comprises one of index-modulated grating structures or loss-modulated grating structures, and the second optical grating comprises the other of the index-modulated grating structures or the loss-modulated grating structures.
3 more elements
Dependencies are inferred from the claim text.