Broad-band spectrometer with high resolution
AssigneeGeneral Atomics
InventorsNeil H. Brooks, Sergey N. Tugarinov, Nicolae N. Naumenko
Life of this patent
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Abstract
A spectrometer provides a substantially simultaneous electronic output over a broad spectral range while maintaining a relatively high resolution. The spectrometer uses a fiber-optic transformer having an arcuate one-dimensional input region, associated with the image plane of a Rowland circle, and produces a rectangular two-dimensional output image, for illuminating the active area of a two-dimensional CCD sensor.
Claims20
Apparatus for providing an electrical signal representing an optical signal's spectral components, comprising:
- an optical instrument that spectrally disperses the optical signal, substantially in a dispersion plane, such that the signal's spectral components are projected onto a circularly curved image plane oriented perpendicular to the dispersion plane and the spectral components are imaged along an arc of a curved image plane, the arc generally lying in the dispersion plane;
- an optical transformer having an arcuate input surface aligned with the arc and having a substantially flat rectangular output surface, wherein the transformer divides the input surface into a plurality of discrete segments along the arc and optically transforms the segments into a stacked format to form a rectangular image area of stacked segments;
- and
- an electro-optical sensor, responsive to light that is simultaneously emitted from each segment of the rectangular image area, wherein the sensor provides an electrical signal that represents the intensity and position of light emitted from the rectangular image area of stacked segments.
A spectrometer for providing a spectral scan of an optical signal, comprising:
- an entrance slit;
- a diffraction grating that resolves the optical signal onto an arc of a circle;
- an optical transformer that takes the resolved light incident on discrete segments of the arc and spatially redistributes it so that the resolved light emitted by the transformer is in a stacked rectangular format;
- and
- an electro-optical sensor, responsive to the light emitted by the transformer, that provides an electrical signal that represents the intensity and position of the light emitted from the transformer.
A spectrometer for providing a spectral scan of an optical signal, comprising:
- an entrance slit;
- a diffraction grating having a diameter of about 7 centimeters and a radius of curvature of about 25 centimeters, wherein the grating spectrally disperses the optical signal that passes through the entrance slit onto an curved image plane with the dispersed optical signal being imaged along an arc of the image plane that has a height of about 0.65 millimeters and a length of 140 millimeters such that the wavelength corresponding to the optical signal imaged at one end of the arc is approximately 400 nanometers and the wavelength corresponding to the optical signal imaged at another end of the arc is 900 nanometers and the spectral resolution along the arc is about 0.1 nanometers;
- and
- an optical transformer having an arcuate input surface aligned with the arc of the image plane and having a substantially flat rectangular output surface, wherein the transformer's input surface is divided along the arc into a plurality of discrete segments and the transformer optically transforms the segments that lie along the arc into a stack of segments that form a rectangular image area having a height of about 13 millimeters and a width of about 6.7 millimeters;
- wherein the arcuate input surface of the optical transformer, the slit, and the grating lie along the circumference of a Rowland circle having a diameter of about 12.7 centimeters.
Dependencies are inferred from the claim text.