Optical beam steering for tunable laser applications
AssigneeFinisar Corporation
InventorKevin J. McCallion
Life of this patent
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Abstract
A transmitter is disclosed including a laser array comprising a plurality of lasers spatially offset from one another and each having a laser output having a unique wavelength. A first prism is positioned to impart a first angular shift to the laser outputs to produce and a second prism is positioned to impart a second angular shift opposite the first angular shift on the outputs. An index modulating element is coupled to one of the first and second prisms and a controller is electrically coupled to the index modulating element to control an angle of light output form the second prism. An optical spectrum reshaper may be positioned between the second prism and the lens and have at least one transmission edge aligned with the wavelength at least one of the lasers.
Claims20
An optical transmitter comprising:
- a laser array comprising a plurality of lasers spatially offset from one another and each having a laser output having a unique wavelength;
- a first prism positioned to impart a first angular shift to the laser outputs to produce first angularly shifted outputs;
- a second prism positioned to impart a second angular shift to the first angularly shifted outputs to produce second angularly shifted outputs, the second angular shift in a direction opposite the first angular shift;
- an output lens positioned to receive a first output of the second angularly shifted outputs incident on the lens;
- an index modulating element coupled to one of the first and second prisms;
- and
- a controller electrically coupled to the index modulating element, the controller programmed to selectively power the index modulating element an amount effective to alter one of the first and second angular shifts sufficiently to cause a second output of the second angularly shifted outputs to be incident on the lens.
A method for tuning a transmitter to a selected wavelength comprising:
- selecting a laser having the selected wavelength within a tunable range thereof from an array of tunable lasers;
- tuning the selected laser to the selected wavelength;
- tuning an index of refraction of one of a first prism and a second prism, the first prism positioned to receive the output of the selected laser and the second prism positioned to receive an output of the first prism and to at least partially reverse an angular shift in the output of the first prism relative to the output of the laser, an output of the second prism being incident on an optical spectrum reshaper;
- frequency modulating the selected laser such that the output of the laser is frequency modulated;
- and
- transmitting the output of the laser through an optical spectrum reshaper configured to at least partially convert frequency modulation in the output of the laser to amplitude modulation.
Dependencies are inferred from the claim text.