Abstract: A system for collecting gas samples emitted from skin and detecting concentrations of specified components therein. The system includes a collection chamber housing defining an interior space, the collection chamber housing having a gas inlet, a gas outlet, and an opening. The opening is configured for enclosing a skin portion from which to receive an emitted gas sample and sealing the interior space against the skin portion. An inert gas source is connected to the gas inlet, which is capable of allowing inert gas from the inert gas source to flow into the interior space. A gas cell is connected to the gas outlet, which is capable of allowing the inert gas and the gas sample to flow from the interior space into the gas cell. As a laser travels through the gas cell, power and optoacoustic signals are measured and used to determine a concentration of the specified component.

Abstract: A system for collecting gas samples emitted from skin and detecting concentrations of specified components therein. The system includes a collection chamber housing defining an interior space, the collection chamber housing having a gas inlet, a gas outlet, and an opening. The opening is configured for enclosing a skin portion from which to receive an emitted gas sample and sealing the interior space against the skin portion. An inert gas source is connected to the gas inlet, which is capable of allowing inert gas from the inert gas source to flow into the interior space. A gas cell is connected to the gas outlet, which is capable of allowing the inert gas and the gas sample to flow from the interior space into the gas cell. As a laser travels through the gas cell, power and optoacoustic signals are measured and used to determine a concentration of the specified component.

Abstract: A method for detecting component concentrations in human gas emissions such as breath and gas emitted from skin. A gas sample containing a specified component is collected into a gas cell using a pump and a series of valves to draw the gas sample into the cell and control the gas pressure within the cell. A tunable optical radiation beam is passed through the gas cell and the amount of energy absorbed by the specified component may be measured indirectly by taking the difference between the incident and emerging beam energy or directly by optoacoustic methods. Concentrations of the specified component as small as 0.1 ppB may be determined. Additionally, the tunable optical radiation beam may be multiplexed for use with a plurality of systems utilizing the beam for medical purposes.

Abstract: A method and apparatus architecture for detecting gases, particularly hazardous gases which should be detected in miniscule amounts. High sensitivity detection of chemical warfare agents (CWAs) is set forth with very low probability of false positives (PFP) by the use of an innovative laser-photoacoustic spectrometer (L-PAS). Detection of diisopropyl methylphosphonate (DIMP), a decomposition product of Sarin and a relatively harmless surrogate for the nerve gases, is made in the presence of other gases that are expected to be interferences in an urban setting. Detection sensitivity for DIMP in the presence of these interferences of better than 0.45 ppb, which satisfies current homeland and military security requirements is shown as well as the first analysis of optical techniques for the detection of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) in real world conditions.

Abstract: An all optical fiber bit stream reader system for examining the data contents of an optical fiber involving the conversion of a temporal timing signal into a spatially located signal is provided. The invention generally comprises generating and detecting a signal indicating the presence of data, in a manner which is minimally destructive to the data. One embodiment comprises providing a piece of optical fiber that exhibits a nonlinear response through a two photon absorption process and subsequent emission of a photon corresponding to the two photon absorption process. Such a fiber could comprise a conventional doped silica fiber into which an additional dopant has been introduced. Another embodiment involves modifying the index of refraction of the cladding of the optical fiber line. This causes a fraction of the electric field or light pulse guided through the fiber (if present) to be coupled out of the fiber. Thereafter, the pulse can be detected.

Abstract: A method and apparatus architecture for detecting gases, particularly hazardous gases which should be detected in miniscule amounts. High sensitivity detection of chemical warfare agents (CWAs) is set forth with very low probability of false positives (PFP) by the use of an innovative laser-photoacoustic spectrometer (L-PAS). Detection of diisopropyl methylphosphonate (DIMP), a decomposition product of Sarin and a relatively harmless surrogate for the nerve gases, is made in the presence of other gases that are expected to be interferences in an urban setting. Detection sensitivity for DIMP in the presence of these interferences of better than 0.45 ppb, which satisfies current homeland and military security requirements is shown as well as the first analysis of optical techniques for the detection of chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) in real world conditions.

Abstract: A method for detecting component concentrations in human gas emissions such as breath and gas emitted from skin. A gas sample containing a specified component is collected into a gas cell using a pump and a series of valves to draw the gas sample into the cell and control the gas pressure within the cell. A tunable optical radiation beam is passed through the gas cell and the amount of energy absorbed by the specified component may be measured indirectly by taking the difference between the incident and emerging beam energy or directly by optoacoustic methods. Concentrations of the specified component as small as 0.1 ppB may be determined. Additionally, the tunable optical radiation beam may be multiplexed for use with a plurality of systems utilizing the beam for medical purposes.

Abstract: A tunable semiconductor laser includes gain medium, wavelength-selective element and a laser mode matching element. The wavelength-selective element comprises a first light absorbing plate operatively coupled to the laser mode matching element and provided with an array of high reflectivity mirrors as well as a second light absorbing plate with an array of narrow band pass filter mirrors operatively coupled to the high reflectivity mirror array of the first plate. The narrow band pass filter mirror array is disposed over a respective array of apertures in the second plate. The wavelength-selective element also comprises a light reflective plate with an array of retroreflectors and a third light absorbing plate with an array of apertures operatively disposed between the aperture array of the second plate and the retroreflector array.

Abstract: A method for preventing explosions in closed tanks which hold flammable liquids and flammable vapors and air above these liquid fuels comprising filling the ullage with a pressurized gas which not only excludes oxygen from the ullage but also prevents transmission of fire initiating sparks. The method further comprises filling the ullage with an electronegative gas alone or in combination with an inert gas or gases. More specifically, the preferred electronegative gas is sulfur hexafluoride (SF.sub.6) which may also be used in combination with CO.sub.2 and/or N.sub.2. More particularly, the method is directed to the prevention of explosions in aircraft fuel tanks.

Abstract: As the size and consequent thickness of IC packages shrink bowing of the package due to differential contractions becomes a problem. The solution according to this invention is to mold strain relief grooves into the surface of the plastic package.