337 results about "Absorption spectroscopy" patented technology

A method and device for measuring a concentration of a preselected gas in a gas sample are disclosed. The device comprises a Herriott type multipass cell (10) having a center axle (74) and a housing (80A, 80B) surrounding and spaced from the axle to provide a tubular sample cavity (84). The gas sample is pumped through the sample cavity via apertures (154, 156) provided in opposed ends of the axle. A first mirror (44) and a second mirror (46) are supported at opposed ends of the axle. A light source, e.g. a laser or LED, is provided for emitting a light beam into the sample cavity via an entry aperture (30) in the first mirror, the light beam having a wave length at which the preselected gas strongly absorbs. The beam is reflected between the mirrors for a number of times before exiting the cell via an exit aperture (48) in the second mirror and impinging on a detector (52). The device further comprises a reference detector (32) for monitoring the intensity of the unattenuated light beam and a detector for detecting the intensity of light transmitted through the second mirror after a single pass through the cell. The light source is operatively connected to a heat control assembly having a heat sink and the gas sample is passed said heat sink to augment temperature control of the light source.

There is provided a solid-state imaging device including a plurality of pixels that are provided on a semiconductor substrate, and that include a plurality of photoelectric-conversion units and metal oxide semiconductor transistors that selectively read signals from the plurality of photoelectric-conversion units, an organic-photoelectric-conversion film disposed on the plurality of photoelectric-conversion units, and an organic-color-filter layer disposed on the plurality of photoelectric-conversion units. Only a signal corresponding to a first color is extracted through the organic-photoelectric-conversion film. Signals corresponding to a plurality of colors not including the first color are extracted by absorption spectroscopy using the organic-color-filter layer.

An absorption spectrometer provides improved rejection of background radiation signal by employing a frequency-swept laser signal without frequency dithering and performing an effective differentiation of output light from a test cell to eliminate these constant or slowly varying background radiation levels.

A multisensor probe for continuous real-time tissue identification. The multisensor probe includes a tissue penetrating needle, a plurality of sensors useful in characterizing tissue and a position sensor to measure the depth of the needle into the tissue being diagnosed. The sensors include but are not limited to an optical scattering and absorption spectroscopy sensor, an optical coherence domain reflectometry sensor, an electrical impedance sensor, a temperature sensor, a pO2 sensor, a chemical sensor and other sensors useful in identifying tissue. The sensors may take the form of a plurality of optical fibers extending through said needle. A retractable sheath may be disposed around the distal section of the needle to protect the needle when not in use. The sheath retracts when the probe is inserted into tissue and the position of the sheath relative to the needle may be measured to determine the needle's depth. Systems and methods for tissue identification are also provided.