Abstract: A method and apparatus for the photo-acoustic identification and quantification of one or more analyte species present in a gaseous or liquid medium in low concentration utilizing a laser and a resonant optical cavity containing the medium and having within the cavity at least two partially transparent mirrors, one of which is a cavity coupling mirror and one of which is moveably mounted on an assembly responsive to an input signal.

Abstract: A fluorescence imaging system having an enclosure having an optical excitation and detection system and features designed to suppress or reduce background fluorescence. In certain aspects, all or a portion of the interior walls has a material finish and texture that provides a surface that absorbs at least a portion of any impinging excitation light and which has low auto-fluorescing properties. In certain aspects, a baffle structure is provided on the interior of the structure and is configured to mask portions of the interior and reduce the opening through which light impinges on the detector.

Abstract: A system and method to obtain correct gas density and flux measurements using (i) gas analyzer (open-path, or closed-path gas analyzers with short intake tube, or any combination of the two); (ii) fast temperature or sensible heat flux measurement device (such as, fine-wire thermocouple, sonic anemometer, or any other device providing fast accurate gas temperature measurements); (iii) fast air water content or latent heat flux measurement device (such as, hygrometer, NDIR analyzer, any other device providing fast accurate gas water content measurements); (iv) vertical wind or sampling device (such as sonic anemometer, scintillometer, or fast solenoid valve, etc.) and (v) algorithms in accordance with the present invention to compute the corrected gas flux, compensated for T-P effects. In case when water factor in T-P effects is negligible, the fast air water content or latent heat flux measurement device (item iii in last paragraph) can be excluded.

Abstract: Optical feedback assisted cavity enhanced absorption spectroscopy systems and methods for measuring trace gases with improved long-term stability and reproducibility include a laser coupled with a resonant optical cavity containing a gaseous medium and having at least two cavity mirrors and a plurality of optical resonance cavity modes. The laser emits continuous wave laser light with a mean optical frequency of the laser being adjustable over a range of frequencies, and the laser is responsive to optical feedback light emerging from the cavity. The transmissivity of at least one of the cavity mirrors is selected such that the intensity of the optical feedback light impinging on the laser is below a threshold intensity value so as to ensure that a frequency hold interval range of the optical frequency of the laser is smaller than a free spectral range of the cavity.

Abstract: A multi-channel scanning system adapted to implement a low channel cross-talk, extra-wide dynamic range scanning method by scanning the same location more than once, wherein at least one time, the power of the excitation light and detector gain are set to High for at least one of the channels and Low for at least one of the other channels and different settings are used in subsequent scans. The scans of the same channel taken with different High and Low settings are merged together to produce one wider dynamic range image.

Abstract: The present invention provides compounds and methods for attaching fluorescent labels to biological molecules such as nucleotides. The compounds and methods are useful for biological assays including DNA modification reactions.

Abstract: Cavity enhanced absorption spectroscopy systems and methods for detecting trace gases. A laser or other light source that is capable of being frequency-scanned is coupled to a resonance cavity though one of the cavity mirror. When the frequency of the laser light approaches the frequency of one of the cavity modes, the laser begins to fill the cavity to that mode. Optical intensity inside the resonance cavity reflects total cavity loss at the moment when the laser light frequency coincides with the cavity mode transmission peak. The total cavity loss is a sum of the cavity mirror losses and losses caused by absorption of a gas mixture present in the cavity. The intra-cavity optical power also depends on the coupling efficiency of the laser beam to the particular cavity mode.

Abstract: Compounds and methods are disclosed that are useful for noninvasive imaging in the near-infrared (NIR) spectral range. The NIR is highly sensitive for tumor detection and tracking. The application discloses targeting a tumor-enriched cell surface receptor with a ligand-conjugated fluorescent probe, which specifically allows detection of the tumor relative to the negligible animal autofluorescence.

Abstract: Systems and methods for measuring the isotope ratio of one or more trace gases and/or components of gas mixtures such as different gas species present in a gas mixture. The system includes a resonant optical cavity having two or more mirrors and containing a gas, the cavity having a free spectral range that equals the difference between frequencies of two measured absorption lines of different gas species in the gas, or of two different isotopes, divided onto an integer number. The system includes a continuous-wave tunable laser optically coupled with the resonant optical cavity and a detector system for measuring an absorption of laser light by the gas in the cavity. The detector system includes a photo-detector to measure an intensity of the intra-cavity light, or both a photo-acoustic sensor to measure photo-acoustic waves generated in the cavity and a photo-detector to measure an intensity of the intra-cavity light.

Abstract: A method and apparatus for the photo-acoustic identification and quantification of one or more analyte species present in a gaseous or liquid medium in low concentration utilizing a laser and a resonant optical cavity containing the medium and having within the cavity at least two partially transparent mirrors, one of which is a cavity coupling mirror and one of which is moveably mounted on an assembly responsive to an input signal.

Abstract: Compounds and methods are disclosed that are useful for noninvasive imaging in the near-infrared spectral range. The cyanine compounds of Formula I are presented: wherein Q is a portion of a polymethine bridge: Also included are bioconjugates of the compounds of Formula I, methods of labeling biomolecules with the compounds, and methods of imaging.

Abstract: A multi-pass optical cell with an actuator for actuating a reflective surface is provided. In one preferred embodiment, an apparatus is provided comprising a first reflective surface, a second reflective surface, and a support structure supporting the first and second reflective surfaces. The support structure positions the first and second reflective surfaces to create an optical cell. The apparatus also comprises a source and a detector, which are positioned such that light emitted from the source is reflected in the optical cell at least one time between the first and second reflective surfaces before reaching the detector. The apparatus further comprises an actuator coupled with and operative to actuate the first reflective surface. In some embodiments, the actuator rotates the first reflective surface. Also, in some embodiments, the multi-pass optical cell is an open path multi-pass optical cell, while, in other embodiments, the multi-pass optical cell is a closed path multi-pass optical cell.

Abstract: A method and apparatus for the photo-acoustic identification and quantification of one or more analyte species present in a gaseous or liquid medium in low concentration utilizing a laser and a resonant optical cavity containing the medium and having within the cavity at least two partially transparent mirrors, one of which is a cavity coupling mirror and one of which is moveably mounted on an assembly responsive to an input signal.

Abstract: Methods, devices, and systems for measuring carbon assimilation based on simultaneous or near-simultaneous measurements of chlorophyll fluorescence and stomatal conductance of plant. A sample containing chlorophyll, such as a plant leaf, is illuminated with light, e.g., in the form of a single saturating pulse or multiple pulses, and chlorophyll fluorescence and stomatal conductance of the chlorophyll sample are measured. A porometer or infra-red gas analyzer is used to measure stomatal conductance and a photodetector is used to measure fluorescence. A carbon assimilation value for the chlorophyll sample is determined using the measured chlorophyll fluorescence and the measured stomatal conductance.

Abstract: Optical mirror elements having a diffusive backing, methods for making such optical mirror elements, and devices incorporating such optical mirror elements. The optical mirror element typically includes a first, reflective surface, and a second surface having uneven or granular features, wherein light passing through the first surface is diffusely reflected by the uneven or granular features of the second surface. The optical mirror elements are particularly well suited for use in Herriott Cell arrangements in gas analyzers.

Abstract: Compounds and methods are disclosed that are useful for noninvasive imaging in the near-infrared (NIR) spectral range. The NIR is highly sensitive for tumor detection and tracking. The application discloses targeting a tumor-enriched cell surface receptor with a ligand-conjugated fluorescent probe, which specifically allows detection of the tumor relative to the negligible animal autofluorescence.

Abstract: Gas analyzer systems and methods for measuring concentrations of gasses and in particular dry mole fraction of components of a gas. The systems and method allow for rapid measurement of the gas density and/or dry mole fraction of gases for a number of environmental monitoring applications, including high speed flux measurements. A novel coupling design allows for tool-free removal of a cell enclosing a flow path to enable in field cleaning of optical components.

Abstract: Systems and methods for producing background-reduced fluorescence imaging signals include an illumination system that provides illumination light from an illumination source to a targeted area on the sample platform, a sensor adapted to detect light and having an array of sensing locations, and collection optics arranged and configured to project light emanating from the sample platform onto the sensor. In typical operation, light from the targeted area is projected onto a first portion of the sensor comprising a first plurality of the sensing locations and light from proximal to the targeted area on the platform is projected onto a second portion of the sensor comprising a second plurality of the sensing locations, and a second signal detected by the second portion of the sensor is subtracted from a first signal detected by the first portion of the sensor to produce a background-reduced signal, e.g., a signal with reduced background related noise.

Abstract: Compounds and methods are disclosed that are useful for noninvasive imaging in the near-infrared (NIR) spectral range. The NIR is highly sensitive for tumor detection and tracking. The application discloses targeting a tumor-enriched cell surface receptor with a ligand-conjugated fluorescent probe, which specifically allows detection of the tumor relative to the negligible animal autofluorescence.

Abstract: Gas analyzer systems and methods for measuring concentrations of gasses and in particular dry mole fraction of components of a gas. The systems and method allow for rapid measurement of the gas density and/or dry mole fraction of gases for a number of environmental monitoring applications, including high speed flux measurements. A novel coupling design allows for tool-free removal of a cell enclosing a flow path to enable in field cleaning of optical components.