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US 9,372,250 B2Granted
Chip-scale star tracker
AssigneeThe Charles Stark Draper Laboratory, Inc.
InventorsJuha-Pekka Laine, Gregory P. Blasche, Murali V. Chaparala, Robin Dawson, Benjamin Lane, Stephen P. Smith, Erik Waldron
Life of this patent
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Abstract
A chip scale star tracker that captures plane-wave starlight propagating in free space with a wafer-thin angle-sensitive broadband filter-aperture, and directs the light into a waveguide structure for readout. Angular information about the star source is determined from characteristics of the starlight propagating in the waveguide. Certain examples include internal propagation-constant-based baffling to elimination stray light from extreme angles.
Claims20
A star tracker comprising:
- a layered wafer substrate;
- a planar waveguide patterned on the layered wafer substrate;
- a coupling grating disposed on a surface of the planar waveguide and configured to couple incident free-space starlight into the planar waveguide to provide coupled starlight, the planar waveguide being configured to propagate the coupled starlight;
- and
- a detector system coupled to the planar waveguide and configured to detect and analyze the coupled starlight propagated by the planar waveguide to determine at least one of an azimuth angle and an elevation angle of a star that is a source of the free-space starlight.
2 more elements
A star tracker comprising:
- a wafer substrate including at least one dielectric layer;
- a coupling structure patterned on a surface of the wafer substrate and configured to couple starlight into the at least one dielectric layer;
- a plurality of readout waveguides, each configured to propagate the starlight coupled into the at least one dielectric layer by the coupling structure, wherein a mode of propagation of the starlight in each readout waveguide is at least partially determined by an angle of incidence of the starlight on the coupling structure;
- and
- a detector system coupled to the plurality of readout waveguides and configured to analyze the starlight propagated in the plurality of readout waveguides to produce an image of a star field that is a source of the starlight.
2 more elements
Dependencies are inferred from the claim text.