Method and apparatus for spectrum analysis and encoder
OwnerThomas W. Haglerinventor
Life of this patent
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Abstract
A disc serving as a spatial radiation modulator has dispersed radiation filters thereon. Each filter has a transmittance or reflectance modulation function of the form sin2(mθ+pπ/4), where m is a positive integer and p has one of the four values 0, 1, 2, 3. A radiation beam including selected wavelength components is diffracted into an elongated image dispersed according to wavelength. Different wavelength components are focused onto different filters on the modulator and are encoded by correspond filters. Since the modulation functions of the filters are orthogonal to one another, it is possible to extract the amplitude of each wavelength component after it has been encoded or modulated by corresponding filter from the total detected signal during one measurement.
Claims14
A two dimensional spatial radiation modulator adapted to be rotated about a rotation axis to modulate at least one component of an incident radiation beam to encode said beam, said modulator comprising a substrate and at least one radiation filter located at a radius from said rotation axis, said filter comprising an annular region substantially encompassing a plurality of pixels having optical characteristics substantially different from said substrate, said pixels being patterned substantially within said annular region to modulate the intensity of a corresponding component substantially only along an azimuthal axis to provide an encoded component, wherein the amplitude of said encoded component changes between three or more substantially distinct levels of contrast as the substrate is rotated about said rotation axis.
A two dimensional spatial radiation modulator adapted to be rotated about a rotation axis to modulate at least one component of an incident radiation beam to encode said beam, said modulator comprising a substrate and at least one radiation filter located at a radius from said rotation axis and having radial width, said filter having substantially continuously variable optical characteristics along an azimuthal axis, said optical characteristics being continuously varied to modulate the intensity of said component as a substantially smooth function of a rotation angle of the modulator about said rotation axis.
Dependencies are inferred from the claim text.