Photonic crystal based rotation sensor
AssigneeNorthrop Grumman Guidance and Electronics Company, Inc.
InventorsDaniel A. Tazartes, Kenneth D. Marino
Life of this patent
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Abstract
A gyroscope having photonic crystals for sensing rotation uses the Sagnac effect to determine angular motion. The gyroscope comprises a photonic crystal capable of guiding counter-propagating light beams in a closed path. A light source, coupling, and detection apparatus permits detection of phase changes between the counter-propagating beams, thereby permitting measurement of angular rotation. The photonic crystal comprises a periodic structure of pillars and voids which creates a photonic bandgap waveguide within which light waves in the proper wavelength range propagate with low loss.
Claims8
A rotation sensor comprising:
- a light source;
- a coupler for splitting light from the light source into a first beam and a second beam;
- a first light guide having an introduction point and an end, the first light guide formed in a spiral shape and having a photonic crystal structure receiving the first beam at the introduction point of the first light guide, the photonic crystal structure of the first light guide being a plurality of pillars, positioned transverse to propagation of the first beam, and a pair of crystal slabs, for creating a predefined path for the first beam;
- a second light guide having an introduction point and an end, the second light guide formed in a spiral shape adjacent and concentric with the first light guide in the same plane as the first light guide, the second light guide having a photonic crystal structure receiving the second beam at the introduction point of the second light guide, the photonic crystal structure of the second light guide being a plurality of pillars, positioned transverse to propagation of the second beam, and a pair of crystal slabs, for creating a predefined path for the second beam;
- and
- a turn at the end of the first light guide connected to the end of the second light guide.
Dependencies are inferred from the claim text.