Compact liquid crystal based fourier transform spectrometer system
AssigneeUniversity of Washington
InventorsWei-Chih Wang, Chu-Yu Huang
Life of this patent
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Abstract
Systems and methods for a compact Fourier transform spectrometer. A cell having two transparent walls and containing a liquid crystal medium is placed in a light beam. Applying a voltage across the cell causes the liquid crystal molecules to orient at a certain angle, wherein the angle is a function of the voltage applied. The refractive index if the cell is dependent upon the orientation of the liquid crystal molecules, and from the refractive index of the cell an optical path difference between ordinary and extraordinary waves can be calculated. Accordingly, any suitable optical path difference can be achieved by varying the voltage across the cell for a Fourier transform analysis.
Claims26
An assembly, comprising:
- a cell for altering an optical path distance of a beam of light, the cell comprising—
- a pair of transparent walls on opposite sides of the cell;
- a liquid crystal fluid within the cell, wherein the liquid crystal fluid has a refractive index that depends, at least in part, upon an orientation of molecules of the liquid crystal fluid, and wherein the orientation of the molecules of the liquid crystal fluid depends, at least in part, upon an electric field within the cell;
- a source of electric energy configured to create a variable electric field within the cell;
- a light source configured to direct a beam of light through the cell;
- and
- a detector configured to receive the beam of light after the beam of light has passed through the cell and to measure the optical path difference of the beam of light.
A Fourier transform spectrometer for measuring a refracted beam of light, the spectrometer comprising:
- a light source;
- a detector configured to receive the beam of light from the light source and measure characteristics of the beam of light;
- a cell positioned between the light source and the detector, wherein the cell contains a substance having an index of refraction that is dependent upon an electric field across the cell;
- and
- a power source configured to apply the electric field across the cell in a controllable, variable manner.
A method of manufacturing a cell for a Fourier transform spectrometer, the method comprising:
- forming a pair of cell walls by—
- depositing an electrode layer on a glass substrate, and
- fabricating an orientation layer on the electrode layer;
- placing a spacer between the cell walls;
- placing a liquid crystal material between the cell walls and the spacer;
- forming an epoxy material between the cell walls and around at least a portion of the spacer to seal the liquid crystal material within the cell;
- and
- connecting a power source to the electrode layer on each of the cell walls, wherein the power source is configured to apply a variable electric field across the cell.
Dependencies are inferred from the claim text.