Grating based phase control optical delay line
First Claim
1. An optical interferometric imaging system for imaging a sample comprising:
- an optical source capable of producing an optical signal having an optical spectrum;
an interferometer in communication with said optical source;
a detector in optical communication with said interferometer; and
an optical delay line apparatus in optical communication with said interferometer comprising;
a plurality of optical elements in optical communication with other,wherein at least one of said plurality of optical elements is used to spatially disperse the optical spectrum of the optical signal to provide a spatially dispersed optical signal,wherein at least one of said plurality of optical elements is adjustable to affect the phase delay and the group delay of the optical signal.
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Accused Products
Abstract
An apparatus for performing high speed scanning of an optical delay and its application for performing optical interferometry, ranging, and imaging, including cross sectional imaging using optical coherence tomography, is disclosed. The apparatus achieves optical delay scanning by using diffractive optical elements in conjunction with imaging optics. In one embodiment a diffraction grating disperses an optical beam into different spectral frequency or wavelength components which are collimated by a lens. A mirror is placed one focal length away from the lens and the alteration of the grating groove density, the grating input angle, the grating output angle, and/or the mirror tilt produce a change in optical group and phase delay. This apparatus permits the optical group and phase delay to be scanned by scanning the angle of the mirror. In other embodiments, this device permits optical delay scanning without the use of moving parts.
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Citations
18 Claims
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1. An optical interferometric imaging system for imaging a sample comprising:
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an optical source capable of producing an optical signal having an optical spectrum; an interferometer in communication with said optical source; a detector in optical communication with said interferometer; and an optical delay line apparatus in optical communication with said interferometer comprising; a plurality of optical elements in optical communication with other, wherein at least one of said plurality of optical elements is used to spatially disperse the optical spectrum of the optical signal to provide a spatially dispersed optical signal, wherein at least one of said plurality of optical elements is adjustable to affect the phase delay and the group delay of the optical signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A scanning OCT imaging system comprising:
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an optical source capable of producing an optical signal having an optical spectrum; an interferometer in communication with said optical source; a detector in optical communication with said interferometer; a signal processor in electrical communication with said detector; an optical delay in optical communication with said interferometer, wherein said optical delay comprises adjustable optical elements capable of spatially dispersing said optical signal and affecting an optical group delay of said optical signal; a scanning device capable of adjusting said adjustable optical elements thereby controlling said optical group delay; wherein said interferometer interferometrically combines the delayed optical signal with a portion of the optical signal not transmitted through the apparatus and wherein said detector detects said interferometrically combined signal, producing a substantially zero frequency heterodyne or homodyne signal in response thereto, and wherein said signal processor produces images of the sample in response to said heterodyne or homodyne signal. - View Dependent Claims (17)
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14. A method for producing an image of a sample comprising:
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providing an optical source; providing a detector in optical communication with said optical source; providing an interferometer in communication with said optical source and said detector; providing an interferometer in communication with said optical source and said detector; providing an optical delay line, said optical delay line comprising adjustable optical elements capable of spatially dispersing an optical signal from said optical source and adjusting at least one of the phase delay and optical group delay of said spatially dispersed optical signal, in optical communication with said interferometer; providing a sample in proximity with said interferometer; transmitting a signal from said optical source to said sample and said optical delay line; adjusting said adjustable elements thereby affecting at least one of the phase delay and group delay of optical signal received by said optical delay line; combining signal from the sample and the spatially dispersed, delayed optical signal; detecting the combined signal and producing an image in response to said detection. - View Dependent Claims (15, 16)
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18. A scanning OCT imaging system comprising:
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an optical source capable of producing an optical signal having an optical spectrum; an interferometer in communication with said optical source; a detector in optical communication with said interferometer; a signal processor in electrical communication with said detector;
an optical delay in optical communication with said interferometer,wherein said optical delay comprises adjustable optical elements capable of spatially dispersing said optical signal and affecting an optical group delay of said optical signal; a scanning device capable of adjusting said adjustable optical elements thereby controlling a scan of said optical group delay; wherein said interferometer interferometrically combines the delayed optical signal with a portion of the optical signal not transmitted through the apparatus, wherein said detector detects said interferometrically combined signal, thereby producing a substantially non-zero frequency heterodyne signal during at least a portion of said scan, and wherein said signal processor produces images of the sample in response to said non-zero frequency heterodyne signal.
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Specification