Uses of electromagnetic interference patterns
First Claim
1. A measurement system comprising:
- an electromagnetic radiation diffraction pattern generator for generating a diffraction pattern including intensity maxima and intensity minima, wherein the diffraction pattern generator includes an arrangement of light-transmitting apertures for the transmission and diffraction of light to generate the diffraction pattern; and
an electromagnetic radiation detector, operable to detect at least a part of the diffraction pattern produced by said generator, the detector having an array of detection elements arranged to detect a location of each of a plurality of the intensity maxima and/or intensity minima of the diffraction pattern substantially simultaneously;
wherein the electromagnetic radiation diffraction pattern generator comprises a laser attached to a pinhole array;
wherein the arrangement of light-transmitting apertures comprises five pinholes arranged on the vertices of a regular pentagon or a ring of nineteen pinholes;
wherein the detected locations of the plurality of the intensity maxima and/or intensity minima are substantially translationally aperiodic;
wherein the diffraction pattern is a two dimensional diffraction pattern;
wherein the detection elements are arranged in a two dimensional array at the detector;
wherein the maxima of the diffraction pattern are spaced apart at a pitch equal to at least twice the pitch of the detection elements;
wherein the detector intercepts at least 10 maxima and/or minima in a single detection event;
wherein the detector has at least 10,000 pixels; and
wherein the system is capable of determining a physical property of the system, or a change in a physical property of the system, based on the detected locations of the plurality of the intensity maxima and/or intensity minima.
1 Assignment
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Accused Products
Abstract
Various uses of visible light interference patterns are provided. Suitable interference patterns are those formed by diffraction from patterns of apertures. Typical uses disclosed herein relate to spatial metrology, such as a translational and/or angular position determination system. Further uses include the analysis of properties of the light itself (such as the determination of the wavelength of the electromagnetic radiation). Still further uses include the analysis of one or more properties (e.g. refractive index) of the matter through which the light passes. Part of the interference pattern is captured at a pixellated detector, such as a CCD chip, and the captured pattern compared with a calculated pattern. Very precise measurements of the spacing between maxima is possible, thus allowing very precise measurements of position of the detector in the interference pattern.
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Citations
14 Claims
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1. A measurement system comprising:
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an electromagnetic radiation diffraction pattern generator for generating a diffraction pattern including intensity maxima and intensity minima, wherein the diffraction pattern generator includes an arrangement of light-transmitting apertures for the transmission and diffraction of light to generate the diffraction pattern; and an electromagnetic radiation detector, operable to detect at least a part of the diffraction pattern produced by said generator, the detector having an array of detection elements arranged to detect a location of each of a plurality of the intensity maxima and/or intensity minima of the diffraction pattern substantially simultaneously; wherein the electromagnetic radiation diffraction pattern generator comprises a laser attached to a pinhole array; wherein the arrangement of light-transmitting apertures comprises five pinholes arranged on the vertices of a regular pentagon or a ring of nineteen pinholes; wherein the detected locations of the plurality of the intensity maxima and/or intensity minima are substantially translationally aperiodic; wherein the diffraction pattern is a two dimensional diffraction pattern; wherein the detection elements are arranged in a two dimensional array at the detector; wherein the maxima of the diffraction pattern are spaced apart at a pitch equal to at least twice the pitch of the detection elements; wherein the detector intercepts at least 10 maxima and/or minima in a single detection event; wherein the detector has at least 10,000 pixels; and wherein the system is capable of determining a physical property of the system, or a change in a physical property of the system, based on the detected locations of the plurality of the intensity maxima and/or intensity minima. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A position determination apparatus comprising a measurement system comprising:
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an electromagnetic radiation diffraction pattern generator for generating an diffraction pattern including intensity maxima and intensity minima, wherein the diffraction pattern generator includes an arrangement of light-transmitting apertures for the transmission and diffraction of light to generate the diffraction pattern; and an electromagnetic radiation detector, operable to detect at least a part of the diffraction pattern produced by said generator, the detector having an array of detection elements arranged to detect a location of each of a plurality of the intensity maxima and/or intensity minima of the diffraction pattern substantially simultaneously; wherein the electromagnetic radiation diffraction pattern generator comprises a laser attached to a pinhole array; wherein the arrangement of light-transmitting apertures comprises five pinholes arranged on the vertices of a regular pentagon or a ring of nineteen pinholes; wherein the detected locations of the plurality of the intensity maxima and/or intensity minima are substantially translationally aperiodic diffraction pattern; wherein the diffraction pattern is a two dimensional diffraction pattern; wherein the detection elements are arranged in a two dimensional array at the detector; wherein the maxima of the diffraction pattern are spaced apart at a pitch equal to at least twice the pitch of the detection elements; wherein the detector intercepts at least 10 maxima and/or minima in a single detection event; wherein the detector has at least 10,000 pixels; and wherein and the system is capable of determining a physical property of the system, or a change in a physical property of the system, based on the detected locations of the plurality of the intensity maxima and/or intensity minima.
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13. A wavelength determination apparatus comprising a measurement system comprising:
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an electromagnetic radiation diffraction pattern generator for generating an diffraction pattern including intensity maxima and intensity minima, wherein the diffraction pattern generator includes an arrangement of light-transmitting apertures for the transmission and diffraction of light to generate the diffraction pattern; and an electromagnetic radiation detector, operable to detect at least a part of the diffraction pattern produced by said generator, the detector having an array of detection elements arranged to detect a location of a plurality of the intensity maxima and/or intensity minima of the diffraction pattern substantially simultaneously, wherein the electromagnetic radiation diffraction pattern generator comprises a laser attached to a pinhole array; wherein the arrangement of light-transmitting apertures comprises five pinholes arranged on the vertices of a regular pentagon or a ring of nineteen pinholes; wherein the detected locations of the plurality of the intensity maxima and/or intensity minima are substantially translationally aperiodic; wherein the diffraction pattern is a two dimensional diffraction pattern; wherein the detection elements are arranged in a two dimensional array at the detector; wherein the maxima of the diffraction pattern are spaced apart at a pitch equal to at least twice the pitch of the detection elements; wherein the detector intercepts at least 10 maxima and/or minima in a single detection event; wherein the detector has at least 10,000 pixels; and wherein the system is capable of determining a physical property of the system, or a change in a physical property of the system, based on the detected locations of the plurality of the intensity maxima and/or intensity minima.
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14. A refractive index determination apparatus comprising a measurement system comprising:
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an electromagnetic radiation diffraction pattern generator for generating an diffraction pattern including intensity maxima and intensity minima, wherein the diffraction pattern generator includes an arrangement of light-transmitting apertures for the transmission and diffraction of light to generate the diffraction pattern; and an electromagnetic radiation detector, operable to detect at least a part of the diffraction pattern produced by said generator, the detector having an array of detection elements arranged to detect a location of each of a plurality of the intensity maxima and/or intensity minima of the diffraction pattern substantially simultaneously, wherein the electromagnetic radiation diffraction pattern generator comprises a laser attached to a pinhole array; wherein the arrangement of light-transmitting apertures comprises five pinholes arranged on the vertices of a regular pentagon or a ring of nineteen pinholes; wherein the detected locations of the plurality of the intensity maxima and/or intensity minima are substantially translationally aperiodic; wherein the diffraction pattern is a two dimensional diffraction pattern; wherein the detection elements are arranged in a two dimensional array at the detector; wherein the maxima of the diffraction pattern are spaced apart at a pitch equal to at least twice the pitch of the detection elements; wherein the detector intercepts at least 10 maxima and/or minima in a single detection event; wherein the detector has at least 10,000 pixels; and wherein the system is capable of determining a physical property of the system, or a change in a physical property of the system, based on the detected locations of the plurality of the intensity maxima and/or intensity minima.
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Specification