Abstract: According to the invention, a highly optically dispersive medium is one in which the absolute value of the group index of refraction of the medium is equal to or greater than four. An optical spectroscopic parameter detection and/or measurement apparatus may be in the form of an interferometer, a spectral interferometer, a spectrometer, a wavemeter, a tunable narrowband filter The embodied devices include a highly dispersive medium that appropriately can facilitate either a slow-light effect or a fast-light effect, which is disposed in a propagation path of an electro-magnetic (EM) input field and, a detector disposed in a manner to detect an output field resulting from the input filed interaction with the highly dispersive medium. Methods involve measuring a spectroscopic parameter using an optical spectroscopic parameter detection and/or measurement apparatus that incorporates a highly dispersive medium.

Abstract: An apparatus includes an optical source providing an optical beam; a splitter configured to split the optical beam into a sample beam and a reference beam; a sample path containing a sample material to be analyzed, the sample beam being directed through the sample path so as to interact with the sample material; a reference path containing a reference material, the reference beam being directed through the reference path so as to interact with the reference material; a disperser configured to receive the sample beam after it exits the sample path and to receive the reference beam after it exits the reference path, the disperser outputting a dispersed sample beam and a dispersed reference beam; and a photodetector disposed to receive the dispersed sample beam and the dispersed reference beam and outputting electrical signals comprised of data indicative of a spectra of the sample beam after it exits the sample path and a spectra of the reference beam after it exits the reference path.

Abstract: An optical coherence tomography system and method with integrated pressure measurement. In one embodiment the system includes an interferometer including: a wavelength swept laser; a source arm in communication with the wavelength swept laser; a reference arm in communication with a reference reflector; a first photodetector having a signal output; a detector arm in communication with the first photodetector, a probe interface; a sample arm in communication with a first optical connector of the probe interface; an acquisition and display system comprising: an A/D converter having a signal input in communication with the first photodetector signal output and a signal output; a processor system in communication with the A/D converter signal output; and a display in communication with the processor system; and a probe comprising a pressure sensor and configured for connection to the first optical connector of the probe interface, wherein the pressure transducer comprises an optical pressure transducer.

Abstract: A solid-state imaging device includes a plurality of photoelectric conversion elements provided at a surface portion of a semiconductor substrate by being arranged in a form of a two-dimensional array, spectral elements each provided on a number of the photoelectric conversion elements which are arranged linearly, a trapezoidal opening which is longitudinally elongated in a direction from a base toward an upper side thereof and which introduces incident light to the number of the photoelectric conversion elements being provided in each of the spectral elements, so as to cause spectral separation in the longitudinal direction by interference between the incident light and light reflected on inner side surfaces of the trapezoidal opening and a signal reading unit for reading a signal which is detected by each of the number of the photoelectric conversion elements arranged in the longitudinal direction by receiving the light incident through the trapezoidal opening.

Abstract: The invention proposes a detection chamber (5) comprising a fluid-tight measurement volume (20) the size of which can be varied using a movable wall portion (15). Such a detection chamber (5) allows compression of the object to be imaged as well as the use of a matching medium to fill the space inside the measurement volume (20) not filled by the object to be imaged.

Abstract: A preferred embodiment biosensor is a multi-layer micro-porous thin film structure. Pores in a top layer of the micro-porous thin film structure are sized to accept a first molecule of interest. Pores in a second layer of the micro-porous thin film structure are smaller than the pores in the top layer and are sized to accept a second molecule of interest that is smaller than the first molecule of interest. The pores in the second layer are too small to accept the first molecule of interest. The pores in the top layer and the pores in the second layer are sized and arranged such that light reflected from the multi-layer micro-porous thin film structure produces multiple superimposed interference patterns that can be resolved. In preferred embodiments, the multi-layer micro-porous thin film structure is a porous silicon thin film multi-layer structure formed on a silicon substrate, such as a silicon wafer. Specific and nonspecific binding can be detected with biosensors of the invention.

Abstract: A system for measuring a property of a sample includes an actuation device disposed on a substrate and includes a flexible surface spaced apart from the substrate and configured so as to allow placement of the sample thereupon. The actuation device also includes a vertical actuator that is configured to cause the flexible surface to achieve a predetermined displacement from the substrate when a corresponding potential is applied thereto. A sensing probe is disposed so as to be configured to interact with the sample thereby sensing the property of the sample.

Abstract: A system and method for creating a unique optical signature that uses a plurality of optical signature chambers containing fluids having differing optical properties, for example differing indices of refraction, that produce different individual optical signatures for each chamber. If the chambers are broken causing the fluids to spill or the fluids are otherwise discharged from the chambers, the fluids mix together so one does not know which fluid came from which chamber, thereby preventing replication of the correct optical signatures. This destruction of the optical signatures can occur mechanically, without the application or presence of electrical power.

Abstract: A control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and/or MIIPS unit between a laser oscillator and an output of a laser amplifier.

Abstract: An optical assembly for use in coherent two- or more-dimensional optical spectroscopy includes a beam splitter that splits a base light pulse into first, second, third and fourth light pulse and a delay element that varies the arrival times of the first to fourth light pulses at a sample location with respect to each other. The beam splitter includes a cross-grating a first reflector arranged to receive the first to fourth light pulses emerging from the cross-grating and to reflect the same in parallel to each other, a second reflector arranged to receive the first to fourth light pulses from the delay element and to focus the same at the sample location, wherein the delay element is arranged between first and second reflectors. Also shown is an apparatus including such optical assembly and a method for carrying out two- or more-dimensional optical spectroscopy using the assembly.

Abstract: A system for analyzing optical cavity modes of at least one microcavity or at least one cluster of microcavities, comprises, an apparatus for sensing a change in the condition of or for analyzing the optical cavity modes by utilizing an optical interference of the optical cavity modes.

Abstract: A MEMS-based Fourier Transform (FT) spectrometer is provided. According to an embodiment, the MEMS-based FT spectrometer is an FT infrared (FTIR) spectrometer. The FT spectrometer can include a beam splitter positioned to receive an incoming beam from a light source and split the incoming beam into a first sub-beam and a second sub-beam, a fixed mirror positioned to receive the first sub-beam from the beam splitter, a scanning MEMS mirror positioned to receive the second sub-beam from the beam splitter, and a photodetector, wherein a reflected first sub-beam from the fixed mirror and a reflected second sub-beam from the scanning MEMS mirror recombine at the beam splitter and become directed to the photodetector. According to one embodiment, the photodetector is a MEMS-based IR detector. In addition, the MEMS-based IR detector can be an un-cooled IR detector having a capacitive sensing structure.

Abstract: An optical detection system for sensing one or more samples is provided. The optical detection system comprises a broadband light source that emits a beam comprising a continuous spectrum over a range of wavelengths; a fluidic cell comprising one or more channels that positions the sample so that at least a portion of the beam is directed on the sample to produce a back reflected beam; and a spectrometer that analyzes an interference spectrum of the beam back reflected from the sample.

Abstract: The invention relates to an apparatus for generating a scannable optical delay for a beam of light and an apparatus for Fourier domain optical coherence tomography having said apparatus for generating a scannable optical delay in its reference arm (15). The light beam is directed to a pivotably driven mirror (10) from where it is reflected to a fixed mirror (12), and from there back retro reflected along the reference arm (5). Lens optics (9) are provided to ensure accurate optical alignment in several pivot positions of the pivotably driven mirror (10).

Abstract: The invention discloses an optical interferometer which can be used to provide simultaneous measurements over multiple path lengths and methods to employ such an interferometer as to achieve a variety of functions covering simultaneous measurements at different depths separated by an increment of a multiple differential delay matched in the interferometer as well as imaging. Optical sensors, optical coherence tomography (OCT) set-ups, optical sensing methods and OCT methods are disclosed which can provide: (i) multiple en-face images at several depths with dynamic dispersion compensation, (ii) fast acquisition of cross sections, (iii) fast acquisition of 3D volumes of a scattering object while maintaining dynamic focus; (iv) fast acquisition of long axial measurement profiles, non mechanical, with dynamic focus, range scalable, with applications in tracking and OTDR.

Abstract: An apparatus for detecting vulnerable plaque within a lumen defined by an intraluminal wall is described. The apparatus includes a probe having a distal portion and a proximal portion. The apparatus includes an optical waveguide extending along the probe. The optical waveguide is configured to carry optical radiation between the distal and proximal portions, and has a distal end in communication with the intraluminal wall. The apparatus includes an interferometer coupled to the optical waveguide and configured to provide an interference signal for sub-surface imaging of the intraluminal wall, and a processing module configured to provide spectroscopic information from detected intensity of light collected from the intraluminal wall.

Abstract: We disclose apparatus that includes: (a) an enclosure including an aperture; (b) a prism mounted in the enclosure so that a surface of the prism is exposed through the aperture; (c) an optical assembly contained within the enclosure, the optical assembly including a radiation source and a radiation detector, the source being configured to direct radiation towards the prism and the detector being configured to detect radiation from the source reflected from the exposed surface of the prism; and (d) an electronic processor contained within the enclosure, the electronic processor being in communication with the detector. The apparatus can be configured so that, during operation, the electronic processor determines information about a sample placed in contact with the exposed surface of the prism based on radiation reflected from the exposed prism surface while it is in contact with the sample.

Abstract: Systems and methods for obtaining information on a key in the BB84 (Bennett-Brassard 1984) protocol of quantum key distribution are provided. A representative system comprises a quantum cryptographic entangling probe, comprising a single-photon source configured to produce a probe photon, a polarization filter configured to determine an initial probe photon polarization state for a set error rate induced by the quantum cryptographic entangling probe, a quantum controlled-NOT (CNOT) gate configured to provide entanglement of a signal with the probe photon polarization state and produce a gated probe photon so as to obtain information on a key, a Wollaston prism configured to separate the gated probe photon with polarization correlated to a signal measured by a receiver, and two single-photon photodetectors configured to measure the polarization state of the gated probe photon.

Abstract: Prior art coherent optical wave mixing has permitted two-dimensional maps from which coupled quantum transitions have been identified in molecular samples. However, extended signal accumulation times and computer processing are required for a detailed molecular analysis, which can lead to sample toxicity and difficulties in interpretation. These and other requirements are reduced by an apparatus arranged for the projection of an image that directly encodes quantum couplings from a sample. Such an apparatus includes a source component (36), a diffractive optical component (25) for generating at least three light fields (1, 2, 3) from one light field (23), one or more optical telescopes (26) and (27) wherein the transverse separation between optical paths is modified from that possible to define with a single telescope between common object and image points, a sample (11) containing said image point, and a means for resolving and detecting the angular variation of light emission from a sample.

Abstract: A spectroscopy device that separates input light into a plurality of wavelength ranges. A metal body has a hole or aperture which is open on the upper side. The hole or aperture is formed in a polygonal shape having at least a pair of opposite faces not parallel to each other in horizontal cross-section. Inner side faces of the hole or aperture are finished as mirror like reflection surfaces. Polarized input light inputted from the opening to the hole or aperture is reflected by the reflection surfaces and a standing wave is generated inside of the hole or aperture by self interference, whereby the input light is separated into a plurality of wavelength ranges.

Abstract: A system for scattered light and simultaneous multi-color (e.g., greater than sixteen colors) fluorescence light detecting, and for analyzing, classifying and identifying biological particles and items of interest. A sample to be tested may be entered in a disposable microfluidic cartridge which in turn is insertable in a portable, hand-holdable, or wearable miniaturized cytometer instrument. The present system may be incorporated in the cytometer instrument. It may have significant application relative to biological warfare, environmental substances, the medical field and other fields.

Abstract: The present invention relates to a method for analyzing chromosomes by preparing a chromosome preparation, measuring at least one interference property of the chromosome preparation and characterizing at least one chromosome structure by way of the interference property. Also, the invention relates to the use of a near field microscope for analyzing unstained chromosomes.

Abstract: A mid infrared spectrometer comprises a high brightness broadband source that generates an output with a broad spectral range in the order of hundreds of wave numbers, a wavelength dispersive element and a detector. In one embodiment, the source comprises an array of semiconductor laser devices operating simultaneously. Each device emits light at wavelength different from the wavelengths emitted by the other devices in the array and the devices are arranged so that the combined output continuously covers the broad spectral range. In another embodiment, each of the lasers in the array is a quantum cascade laser device. In still another embodiment, the quantum cascade laser devices in the array are operated in the regime of Risken-Nummedal-Graham-Haken (RNGH) instabilities. In yet another embodiment, each of the lasers in the array is a mode-locked quantum cascade laser device.

Abstract: Increasing signal to noise ratio in optical spectra obtained by spectrophotometers. An interferometer introduces interference effects into a source light beam. A dual beam configuration splits the source beam having the interference effects into a reference beam and a sample beam. The reference beam interacts with a reference substance and is detected by a reference detector. The sample beam interacts with a sample substance and is detected by a sample detector. An optical spectra of the sample is based on the difference between the detected reference beam and the detected sample beam.

Abstract: A microscope comprising: a light sampler for collecting light from a measurement area of a sample; a multi-element detector having a plurality of photoelectric elements, for detecting the light collected by the light sampler, each photoelectric element corresponding to a minute measurement region in the measurement area with one-to-one correspondence; a Fourier transform spectrophotometer as a spectroscope; a data sampler for concurrently sampling intensity data sent from each photoelectric element of the multi-element detector at a timing determined by the Fourier transform spectrophotometer; and a data processor for obtaining time-resolved spectrum data for each minute measurement region according to temporally changed interference light data obtained by the data sampler.

Abstract: An integrated swept wavelength tunable optical source uses a narrowband filtered broadband signal with an optical amplifier and self-tracking filter. This source comprises a micro optical bench, a source for generating broadband light, a tunable Fabry Perot filter, installed on the bench, for spectrally filtering the broadband light from the broadband source to generate a narrowband tunable signal, an amplifier, installed on the bench, for amplifying the tunable signal. The self-tracking arrangement is used where a single tunable filter both generates the narrowband signal and spectrally filters the amplified signal. In some examples, two-stage amplification is provided. The use of a single bench implementation yields a low cost high performance system. For example, polarization control between components is no longer necessary.

Abstract: There is provided a method for referencing and correcting the beating spectrum generated by the interference of the components of a frequency comb source. The proposed method allows monitoring of variations of a mapping between the source and the beating replica. This can then be used to compensate small variations of the source in Fourier transform spectroscopy or in any other interferometry application in order to overcome the accuracy and measurement time limitations of the prior art. Constraints on source stability are consequently reduced.

Abstract: Exemplary systems and methods for obtaining a photoluminescence radiation from at least one portion of a sample can be provided. For example, using the exemplary embodiment, it is possible to receive a first radiation and disperse the first radiation into at least one second radiation and at least one third radiation. The second and third radiations can be provided to different locations of the portion. In addition, it is possible to receive the photoluminescence radiation from the portion based on the second and third radiations.

Abstract: The present invention provides improved methods and apparatuses for accurate measurements using interferometers. A functional relationship between the optical path difference and time is determined from a reference signal from an interferometer. The times at which the interferometer had specific optical path differences can be determined from the functional relationship. Those times can then be used to select times at which the spectroscopic signal from the interferometer was produced at the specific optical path differences. The invention can be applied, as examples, to maintain instrument calibration, and to transfer or compare calibrations or measurements across different interferometers.

Abstract: A static interferometer comprises an entrance pupil, a splitter plate, a first mirror and a second mirror which are arranged in such a way that light beams originating from a collimated source are divided on the splitter plate, reflect on each of the mirrors and recombine while interfering at the output of the interferometer. The interferometer comprises a prismatic plate of index n comprising a variable thickness ej, the first beam passing through the prismatic plate before reflecting on a reflecting surface of the first mirror, the reflecting surface comprising a plurality of zones, each zone j being situated at a mean distance ?j from a reference plane. The reference plane being perpendicular to an optical axis and corresponding to a position of a plane mirror for which the optical path difference between the two interfering reflected beams is zero, each thickness ej being substantially equal to ?j·n/(n?1).

Abstract: In a spectroscopic reflectometer, in order to make it possible to omit a supplementary measurement (specifically, measurement of a calibration sample) which has been needed every time a light reflectance of an inspection work is measured to promote the reduction in measurement time and simplification in measurement configuration, an internal reflection mechanism having a constant light reflectance is arranged inside a head so that light reflected by the internal reflection mechanism is received by a photo-detector, whereby the light reflectance of the inspection work is calculated based on an output value of the photo-detector in a state of having substantially no light introduced, an output value of the photo-detector when a dark sample that substantially reflects no light is used, an output value that is an output value of the photo-detector when a calibration sample of a known light reflectance is used as the object, and an output value of the photo-detector when an inspection work to be measured is used.

Abstract: The invention relates to a method for registering surfaces, using a scanner system comprising a radiation source for emitting electromagnetic radiation (ES), a scanning device for guiding the radiation over the surface in order to scan the latter and a receiver for receiving the radiation (RS) that is reflected by the surface. According to the invention, the radiation is spectrally separated to analyse the surface characteristics and a distance measuring unit is used to derive distance information in parallel from the received radiation.

Abstract: Calibration of an arbitrary spectrometer can use a stable monolithic interferometer as a wavelength calibration standard. Light from a polychromatic light source is input to the monolithic interferometer where it undergoes interference based on the optical path difference (OPD) of the interferometer. The resulting wavelength-modulated output beam is analyzed by a reference spectrometer to generate reference data. The output beam from the interferometer can be provided to an arbitrary spectral instrument. Wavelength calibration of the arbitrary spectral instrument may then be performed based on a comparison of the spectral instrument output with the reference data. By appropriate choice of materials for the monolithic interferometer, a highly stable structure can be fabricated that has a wide field and/or is thermally compensated. Because the interferometer is stable, the one-time generated reference data can be used over an extended period of time without re-characterization.

Abstract: The invention relates to a carrier for a thin layer and a method for the analysis of molecular interactions on and/or in such a thin layer. A thin layer disposed on a carrier is illuminated with electromagnetic radiation from at least one radiation source and a reflected radiation part on boundary surfaces of the thin layer is detected by means of an optoelectronic converter that converts the detected radiation into a frequency- and intensity-dependant photocurrent. A reading voltage is applied to the optoelectronic converter. By changing the reading voltage, the spectral sensitivity of the optoelectronic converter is varied such that a substantially constant photocurrent is obtained. Alternatively or in addition to varying the spectral sensitivity by changing the reading voltage, the reflected radiation part is detected with an optoelectronic converter that is designed as a sensor layer in the carrier.

Abstract: An apparatus for detecting one or more substances includes a radiation source emitting a beam of radiation and also includes a material capable of reflecting the beam of radiation with a first characteristic and capable of reflecting the beam of radiation with a second characteristic when the material interacts with the one or more substances. The apparatus also includes two or more radiation detectors to detect the first and second characteristics of the beam of radiation. A first one of the two or more radiation detectors is adjustably aligned to detect the first and second characteristics of the beam of radiation reflected from a first region of the material. A second one of the two or more radiation detectors is adjustably aligned to detect the first and second characteristics of the beam of radiation reflected from a second region of the material.

Abstract: A method for determining a background noise level includes receiving interferogram data; determining at least one measure of interferogram quality; accumulating said received interferogram data; and generating a background noise level based on said interferogram data and at least one measure of interferogram quality.

Abstract: An optical sample is mounted on a spatial-acquisition apparatus that is placed in or on an enclosure. An incident beam is irradiated on a surface of the sample and the specular reflection is allowed to escape from the enclosure through an opening. The spatial-acquisition apparatus is provided with a light-occluding slider that moves in front of the sample to block portions of diffuse scattering from the sample. As the light-occluding slider moves across the front of the sample, diffuse light scattered into the area of the backside of the light-occluding slider is absorbed by back side surface of the light-occluding slider. By measuring a baseline diffuse reflectance without a light-occluding slider and subtracting measured diffuse reflectance with a light-occluding slider therefrom, diffuse reflectance for the area blocked by the light-occluding slider can be calculated.

Abstract: To achieve an apparatus capable of measuring a light absorption coefficient f a sample with high sensitivity. A ring down spectroscope uses a wavelength-variable femtosecond soliton pulse light source 1. Pulse light is input to a loop optical fiber 6 through a first light waveguide 4 and a wavelength selective switch 5. Ring down pulse light is input to a homodyne detector through the wavelength selective switch 5. On the other hand, pulse light propagating in the first light waveguide 4 is split and input to light waveguides constituting a second light waveguide 20 through an optical directional coupler 8 and a first optical switching element 12. The pulse light propagating in the second light waveguide 20 is input to the homodyne detector as reference light and used for synchronous detection. The plural light waveguides constituting the second light waveguide 20 differ in optical length in accordance with the length of the optical fiber 6, and can slightly change the optical length.

Abstract: The present invention provides apparatuses and methods for sample analysis, such as tissue analysis, that integrate high wavenumber (HW) Raman spectroscopy for chemical composition analysis and spectral-domain optical coherence tomography (SD-OCT) to provide depth and morphological information. Intravascular catheter embodiments and related vascular diagnostic methods are also provided.

Abstract: A non-periodic reflection beamsplitter or reflector for use in an interferometer. The interferometer employs non-periodic reflectors or a non-periodic beamsplitter in order to produce interference patterns to analyze. The non-periodic reflectors or beamsplitters may be concentrically arranged reflectors having equal area. The beamsplitter consists of two adjacent non-periodic structures having complementary reflection and transmission patterns.

Abstract: An FTIR measurement is conducted on a background gas to obtain a single beam spectrum SB(BG) [C] and a synthetic single beam spectrum SSB(BG)[D], and an FTIR measurement is conducted on a sample gas to obtain a single beam spectrum SB(Samp)[E] and a synthetic single beam spectrum SSB(Samp)[F].

Abstract: Measuring of an electro-optic coefficient and a thermo-optic coefficient of an optical device and an optical material, and more specifically, to measurement systems and methods of evaluating the electro-optic and thermo-optic coefficients by using interference fringe measurement techniques, wherein those optical characteristics can be precisely measured over a wide wavelength intended without using a complicated measuring equipment.

Abstract: This invention relates generally to the systems and methods for chemicals detection such as explosives and others, and more particularly to optical devices and the methods of their use based on sensing of gases and residue materials. This sensing includes detection of optical spectrum and relative concentration of the chemical followed by the chemical identification based on these data. The sensing is based on photothermal interferometry method modified by implementation of coherent optical detection using a balanced receiver, where the incoming optical signal is mixed with a local oscillator beam. An additional phase shift is embedded in the local oscillator beam for adaptively negating the background noise in the incoming optical signal thus improving the system performance.

Abstract: A sensor and method for remotely determining a presence of a particular substance based on spectral data of the particular substance is disclosed.

Abstract: A Micro-Electro-Mechanical Systems (MEMS) interferometer is implemented in a Fourier transform spectrometer, which includes a common housing containing the interferometer and a gas cell, possibly including a preconcentrator. The interferometer system includes an optical bench and at least two mirror structures, being patterned from one or more layers on the optical bench and erected to extend substantially perpendicularly to the bench to define two interferometer arms to provide a MEMS interferometer.

Abstract: The present invention provides optical systems and methods for determining a characteristic of a cell, such as cell type, cellular response to a biochemical event, biological state and the like. The methods typically involve using interferometry to observe membrane properties in a cell and then use this information to determine one or more characteristics of a cell. The methods of the invention are useful for applications such as drug screening as well as diagnostic techniques.

Abstract: A high-speed absorption spectrographic system employs a slit-less spectroscope to obtain high-resolution, high-speed spectrographic data of combustion gases in an internal combustion engine allowing precise measurement of gas parameters including temperature and species concentration.

Abstract: A method and apparatus for extracting the vector optical properties of biological samples with micron-scale resolution in three dimensions, using polarization-sensitive optical coherence tomography (PS-OCT). The method measures net retardance, net fast axis, and reflectivity. Polarization sensing is accomplished by illuminating the sample with at least three separate polarization states, using consecutive acquisitions of the same pixel, A-scan, or B-scan. The method can be implemented using non-polarization-maintaining fiber and a single detector. This PS-OCT method reported measures fast axis explicitly. In a calibration test of the system, net retardance was measured with an average error of 7.5° (standard deviation 2.2°) over the retardance range 0° to 180°, and fast axis with average error of 4.8° over the range 0° to 180°.

Abstract: In an interferometer system and a method for its operation, the interferometer system includes an interferometer having an interferometer light source whose emitted radiation is able to be split into a measuring arm and a reference arm, an object to be measured being disposed in the measuring arm, and the interferometer delivering interferometer signals as a function of the position of the object to be measured. In addition, a detecting device is provided for detecting fluctuations in the refractive index of the air in the measuring arm and/or reference arm. The detecting device includes a spectrometer unit; the spectrometer unit has at least one spectrometer light source, as well as at least one spectrometer detector unit.

Abstract: Optical coherence tomography (OCT) is an imaging method which can image with micrometer-scale resolution up to a few millimeters deep into, for example, living biological tissues and preserved tissue samples. An improved apparatus and image reconstruction algorithm for parallel Fourier Domain OCT which greatly eases requirements for interferometer stability and also allows for more efficient parallel image acquisition is provided. The apparatuses and algorithms reconstruct images from interfered, low-coherence, multiwave length signals having a .pi. radian phase difference relative to one another. Other numbers of signals and other phase differences may be alternatively used, with some combinations resulting in higher resolution and image stability. The apparatus also eliminates a need for bulk optics to modulate a phase delay in a reference arm of the optical path. Images may be reconstructed using two spectrometers, where each is coupled to a detector array such as a photodiode array.