Ultra compact spectrometer apparatus and method using photonic crystals
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsDavid Z. Ting, Cory J. Hill, Sumith V. Bandara, Sarath D. Gunapala
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Abstract
The present invention is directed to methods of photonic crystal formation, and to methods and apparatus for using such photonic crystals, particularly in conjunction with detector arrays. Photonic crystal parameters and detector array parameters are compared to optimize the selection and orientation of a photonic crystal shape. A photonic crystal is operatively positioned relative to a plurality of light sensors. The light sensors can be separated by a pitch distance and positioned within one half of the pitch distance of an exit surface of the photonic crystals.
Claims11
A light sensing apparatus, comprising:
- a photonic crystal having a planar entry surface and a planar exit surface, the exit surface adjacent to the entry surface at a first angle;
- a light source, entering the entry surface at a second angle, dispersing from the entry surface into a plurality of separate wavelength beams, wherein the plurality of wavelength beams exit the exit surface at substantially equal distances from each other;
- one or more transparent or translucent members positioned on the exit surface of the photonic crystal;
- and,
- a plurality of light detectors arranged to measure the plurality of wavelength beams on the one or more transparent or translucent members.
A light sensing apparatus, comprising:
- a photonic crystal having a planar entry surface and a planar exit surfaces, the exit surface adjacent to the entry surface at a first angle;
- a light source, entering the entry surface at a second angle, dispersing from the entry surface into a plurality of separate wavelength beams, wherein the plurality of wavelength beams exit the exit surface at substantially equal distances from each other;
- and,
- a plurality of light detectors arranged to measure the plurality of wavelength beams at the exit surface.
A method of normalizing distance points where at least three light beams having different wavelengths exiting a photonic crystal resulting from a light source entering the photonic crystal, comprising the steps of:
- introducing the light source at a first angle to a planar entry surface of the photonic crystal wherein the light source disperses into at least three light beams having different wavelengths, beam angles formed between each adjacent light beam, said beam angles being unequal;
- providing a planar exit surface adjacent to the entry surface at a second angle, the second angle comprising between 70 and 130 degrees, wherein the at least three light beams exit;
- adjusting the first and second angles.
Dependencies are inferred from the claim text.