Single facet laser sources
AssigneeCisco Technology, Inc.
InventorsMatthew J. Traverso, Dominic F. Siriani, Mark Webster
Life of this patent
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Abstract
The embodiments herein describe a single-frequency laser source (e.g., a distributed feedback (DFB) laser or distributed Bragg reflector (DBR) laser) that includes a feedback grating or mirror that extends along a waveguide. The grating may be disposed over a portion of the waveguide in an optical gain region in the laser source. Instead of the waveguide or cavity being linear, the laser includes a U-turn region so that two ends of the waveguide terminate at the same facet. That facet is coated with an anti-reflective (AR) coating.
Claims18
A laser source, comprising:
- a facet coated with an anti-reflective (AR) coating;
- an intermediate region;
- a U-turn region, wherein the intermediate region is between the facet and the U-turn region;
- a waveguide extending through the facet, the intermediate region, and the U-turn region, wherein a first portion of the waveguide in the U-turn region changes direction such that the waveguide exits the U-turn region in an opposite direction than the first portion of the waveguide entered the U-turn region, wherein first and second ends of the waveguide terminate at the facet;
- and
- a grating disposed over a second portion of the waveguide, wherein the grating and the second portion extend through both the intermediate region and the U-turn region,
- wherein at least one of the intermediate region and the U-turn region provides optical gain to a signal propagating in the waveguide.
An optical system, comprising:
- a laser source comprising:
- a facet coated with an anti-reflective (AR) coating,
- an intermediate region,
- a U-turn region,
- a waveguide extending through the facet, the intermediate region, and the U-turn region, wherein a first portion of the waveguide in the U-turn region changes direction such that the waveguide exits the U-turn region in an opposite direction than the first portion of the waveguide entered the U-turn region, wherein first and second ends of the waveguide terminate at the facet, and
- a grating disposed over a second portion of the waveguide, wherein the grating and the second portion extend through both the intermediate region and the U-turn region;
- and
- a photonic chip comprising:
- a first optical coupler aligned to the laser source to receive a first optical signal emitted from the first end of the waveguide via the facet, and
- a second optical coupler aligned to the laser source to receive a second optical signal emitted from the second end of the waveguide via the facet.
Dependencies are inferred from the claim text.