Vcsel enabled active resonator gyroscope
AssigneeHoneywell International Inc.
InventorWei Yang
Life of this patent
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Abstract
A interferometric optical gyroscope includes an active resonator comprising a half cavity vertical cavity surface emitting laser (half-VCSEL) operating as one of the mirrors that form the ring resonator. The half-VCSEL includes a bottom mirror stack and active layers formed on the bottom mirror stack and has a surface opposite the bottom mirror stack. Lack of a top mirror stack typically found in a VCSEL prevents the half-VCSEL from lasing, thus the half-VCSEL forms a reflective amplifier for the light circulating in the resonator. A single or multiple external light sources can be used to induce two counter-propagating beams in the resonator. Higher finesse due to the internal gain in the resonator enhances the sensitivity of the gyroscope.
Claims20
A half vertical cavity surface emitting laser, comprising:
- a bottom mirror stack;
- and
- active layers formed on said bottom mirror stack and having a surface opposite the bottom mirror stack;
- wherein lack of a top mirror stack typically found in a vertical cavity surface emitting laser prevents the half vertical cavity surface emitting laser from lasing, thus the half vertical cavity surface emitting laser forms a reflective amplifier wherein the bottom mirror stack acts as a mirror for reflecting light generated in the active layers through the surface.
An active resonator gyroscope, comprising:
- an active resonator further comprising at least three mirrors and at least one of the mirrors is a half cavity vertical cavity surface emitting laser operating as an active mirror and the rest are passive mirrors;
- external light beam 1 at optical frequency f1;
- external light beam 2 at optical frequency f2;
- and
- means to feed light beam 1 and light beam 2 into said active resonator in counter-rotating directions and creating two counter-rotating beams within the active resonator;
- and
- photo detectors D1 and D2 for detecting intensity of the two beams via one or two of the passive mirrors;
- wherein f1 and f2 are locked-in with one or two different resonant frequencies of the resonator using outputs from the photo detector D1 and D2, and rotation rate of the gyroscope is correlated to f1-f2.
Dependencies are inferred from the claim text.