Abstract:
A system and method for sensing a target substance in a medium by directing at least first and second beams of radiation to intersect within the medium and establish one or more sensing volumes. The beams have different frequencies to generate a beat frequency at the sensing volume. A selected optical effect, based on an optical property of the target substance within the sensing volume, on the first and second beams is detected at at least one selected spectral line. A signal is generated representative of the selected optical effect, such as absorbance or fluorescence, and the portion of the signal which is substantially at the beat frequency is combined with at least one selected value to determine the amount of the target substance.
Abstract:
Light is collected from a sample that is to be imaged, such as tissue or the like, and made to undergo self-interference, e.g., on a detector. An imaging system may include a low coherence light source arranged for illuminating the sample, and an interferometer arranged to receive the light collected from the sample and to pass it to a detector. The interferometer includes a beam divider that directs the radiation collected from the sample along two paths, phase-delaying one beam relative to another and then recombining the beams on a detector. A processor may be coordinated with the phase delay and in some embodiments with spatial scanning or detector array addresses, and operates on the signal from the detector to form a tomographic image of the sample illuminated tissue. By constructing an image based upon interference the interferometric signal from of the split and then recombined radiation collected from the sample signal, rather than interference of a source reference and a return signal, the invention is able to image with light naturally emitted by the sample. , or with wavelength-shifted, delayed or induced light signals of different types, allowing new modalities of diagnostic and other imaging of the sample and its structure. A processor generates one or more images of the structure being viewed, and may create images in registry from different (for example, close but separable) wavelengths. Some systems may operate without an illumination source or may apply other stimuli to evoke emission from the sample.
Abstract:
Light from a tissue sample undergoes self-interference on a detector. A low coherence light source may illuminate the sample, and an interferometer receives light from the sample, divides and directs the received light along two paths, phase-delaying one and recombining the beams on a detector to form a signal. A processor coordinated with the phase delay and optionally with spatial scanning or detector array addresses, converts the signal to a tomographic image. Using self-interfering radiation from the sample, rather than interference of a reference source and a return signal, permits imaging with light naturally emitted by the sample, or with wavelength-shifted, delayed or induced light signals, allowing new diagnostic imaging modalities. The processor may create images in registry from different (for example, close but separable) wavelengths. Systems may also operate without an illumination source or may apply other stimuli to evoke emission from the sample.
Abstract:
Diffraction grating based fiber optic interferometric systems for use in optical coherence tomography, wherein sample and reference light beams are formed by a first beam splitter and the sample light beam received from a sample and a reference light beam are combined on a second beam splitter. In one embodiment, the first beam splitter is an approximately 50/50 beam splitter, and the second beam splitter is a non 50/50 beam splitter. More than half of the energy of the sample light beam is directed into the combined beam and less than half of the energy of the reference light beam are directed into the combined beam by the second beam splitter. In another embodiment, the first beam splitter is a non 50/50 beam splitter and the second beam splitter is an approximately 50/50 beam splitter. An optical circulator is provided to enable the sample light beam to bypass the first beam splitter after interaction with a sample. Two combined beams are formed by the second beam splitter for detection by two respective detectors. More than half of the energy of the light source provided to the first beam splitter is directed into the sample light beam and less than half of the energy is directed into the reference light beam. The energy distribution between the sample and reference light beams can be controlled by selection of the characteristics of the beam splitters.
Abstract:
Apparatus including a broadband illumination source and a confocal optical system. The confocal optical system is configured and arranged to receive a portion of light projected onto an object by the broadband illumination source. The apparatus can include an illumination source, a confocal optical system, and at least one detector configured and arranged to receive angularly separated light corresponding to a confocal volume. There is also provided a light scattering spectroscopic device including a broadband illumination source, a two-dimensional detector, and a spectral separation device configured and arranged to receive scattered light from an object and to direct at least a portion of the scattered light onto the two-dimensional detector. The method and apparatus can combine confocal microscopy techniques with light scattering spectroscopy techniques to create a confocal light scattering spectroscopy (CLSS) system.
Abstract:
Light is collected from a sample that is to be imaged, such as tissue or the like, and made to undergo self-interference, e.g., on a detector. An imaging system may include a low coherence light source arranged for illuminating the sample, and an interferometer arranged to receive the light collected from the sample and to pass it to a detector. The interferometer includes a beam divider that directs the radiation collected from the sample along two paths, phase-delaying one beam relative to another and then recombining the beams on a detector. A processor may be coordinated with the phase delay and in some embodiments with spatial scanning or detector array addresses, and operates on the signal from the detector to form a tomographic image of the sample illuminated tissue. By constructing an image based upon interference the interferometric signal from of the split and then recombined radiation collected from the sample signal, rather than interference of a source reference and a return signal, the invention is able to image with light naturally emitted by the sample, or with wavelength-shifted, delayed or induced light signals of different types, allowing new modalities of diagnostic and other imaging of the sample and its structure. A processor generates one or more images of the structure being viewed, and may create images in registry from different (for example, close but separable) wavelengths. Some systems may operate without an illumination source or may apply other stimuli to evoke emission from the sample.
Abstract:
Diffraction grating based fiber optic interferometric systems for use in optical coherence tomography, wherein sample and reference light beams are formed by a first beam splitter and the sample light beam received from a sample and a reference light beam are combined on a second beam splitter. In one embodiment, the first beam splitter is an approximately 50/50 beam splitter, and the second beam splitter is a non 50/50 beam splitter. More than half of the energy of the sample light beam is directed into the combined beam and less than half of the energy of the reference light beam are directed into the combined beam by the second beam splitter. In another embodiment, the first beam splitter is a non 50/50 beam splitter and the second beam splitter is an approximately 50/50 beam splitter. An optical circulator is provided to enable the sample light beam to bypass the first beam splitter after interaction with a sample. Two combined beams are formed by the second beam splitter for detection by two respective detectors. More than half of the energy of the light source provided to the first beam splitter is directed into the sample light beam and less than half of the energy is directed into the reference light beam. The energy distribution between the sample and reference light beams can be controlled by selection of the characteristics of the beam splitters.
Abstract:
Diffraction grating based fiber optic interferometric systems for use in optical coherence tomography, wherein sample and reference light beams are formed by a first beam splitter and the sample light beam received from a sample and a reference light beam are combined on a second beam splitter. In one embodiment, the first beam splitter is an approximately 50/50 beam splitter, and the second beam splitter is a non 50/50 beam splitter. More than half of the energy of the sample light beam is directed into the combined beam and less than half of the energy of the reference light beam are directed into the combined beam by the second beam splitter. In another embodiment, the first beam splitter is a non 50/50 beam splitter and the second beam splitter is an approximately 50/50 beam splitter. An optical circulator is provided to enable the sample light beam to bypass the first beam splitter after interaction with a sample. Two combined beams are formed by the second beam splitter for detection by two respective detectors. More than half of the energy of the light source provided to the first beam splitter is directed into the sample light beam and less than half of the energy is directed into the reference light beam. The energy distribution between the sample and reference light beams can be controlled by selection of the characteristics of the beam splitters.
Abstract:
A method according to an embodiment of the invention includes receiving a first optical image from an endoscope having a plurality of imaging fibers. A spatial frequency is identified that is associated with the plurality of imaging fibers. A second optical image is received from the endoscope. The spatial frequency is filtered from the second optical image. A method according to another embodiment includes producing an optical image of at least a portion of a body lumen using a fiberscope. The optical image is transmitted to a video camera coupled to the fiberscope. A honeycomb pattern associated with a fiber bundle of the fiberscope is removed from the optical image. In some embodiments, the honeycomb pattern can be removed in substantially real time. In some embodiments, prior to producing the optical image, a calibration cap is coupled to the fiberscope and used in a calibration process.
Abstract:
Diffraction grating based fiber optic interferometric systems for use in optical coherence tomography, wherein sample and reference light beams are formed by a first beam splitter and the sample light beam received from a sample and a reference light beam are combined on a second beam splitter. In one embodiment, the first beam splitter is an approximately 50/50 beam splitter, and the second beam splitter is a non 50/50 beam splitter. More than half of the energy of the sample light beam is directed into the combined beam and less than half of the energy of the reference light beam are directed into the combined beam by the second beam splitter. In another embodiment, the first beam splitter is a non 50/50 beam splitter and the second beam splitter is an approximately 50/50 beam splitter. An optical circulator is provided to enable the sample light beam to bypass the first beam splitter after interaction with a sample. Two combined beams are formed by the second beam splitter for detection by two respective detectors. More than half of the energy of the light source provided to the first beam splitter is directed into the sample light beam and less than half of the energy is directed into the reference light beam. The energy distribution between the sample and reference light beams can be controlled by selection of the characteristics of the beam splitters.