USA As Represented by Secretary of the Navy

John F Giuliani

Terence W Barrett

Henry Wohltjen

Charles L Marquardt

Abe Auerbach

In an external lasing dye sensor system, a stream of lasing dye free-flows cross an open area inside a chamber. An air sample comprising chemical vapor contaminants is pumped or drawn into the chamber. A laser beam is introduced into the chamber intersecting the lasing dye. A chemical reaction between the contaminants and the lasing dye result in a change in the emission spectra of the lasing dye. The change in emission spectra is detected and thus provides an improved apparatus for detecting low concentrations of chemical vapors in an air sample.

Lasing dye sensor for chemical vapors

In a lasing dye sensor system, a stream of lasing dye freeflows across an ea open to the atmosphere. A chemical reaction between contaminants in the atmosphere and the lasing dye result in the change of emission spectra of the lasing dye. The change in emission spectra is detected and provides an improved apparatus and method for detecting low concentrations of chemical vapors in the atmosphere.

Method for detecting chemical vapors using a lasing dye sensor

A device for detecting small amounts of alkanes such as methane, ethane, propane, and butane gases, comprising an optical waveguide and a light source for propagating light therethrough; apparatus for obtaining samples of air to be tested; apparatus for adding water vapor to these air samples to yield gas mixtures with at least a 30% relative humidity; and means for flowing these mixtures over the surface of the optical waveguide at a rate sufficient to favor condensation of the mixture on the waveguide surface to thereby form a thin film thereon. The presence of alkanes is determined by detecting the intensity of the light after propagation through the optical waveguide and then comparing that detected intensity to a reference. In a preferred embodiment, the optical waveguide is an optical glass capillary in which the surface is closed in a lens-like configuration at the detector end.

Optical waveguide sensor for methane gas

An optical device for obtaining a 3-dimensional signature or a plurality of 2-dimensional signatures for a given sample in order to detect predetermined chemical agents. The device comprises a light channel with a first sensing optical fiber with a coating thereon which changes its absorptive and refractive properties in the presence of a predetermined chemical agent, and a second light channel with a reference optical fiber isolated from the sample. A scanning monochromator is utilized to apply light beams to the sensing and reference fibers, and an optical detector is used to cross-correlate the outputs from the sensing and reference fibers. A variable optical delay line is disposed in one of the fiber channels in order to scan from 0.degree. to 360.degree. in phase shift for each light frequency. A 2-dimensional cross-correlation is obtained for this scan at this frequency. The scanning monochromator is set to run through a series of light frequencies in a given bandwidth. A 2-dimensional cross-correlation phase scan is obtained at each different light frequency. A 3-dimensional cross-correlation may then be obtained (cross-correlation value vs frequency vs phase delay) to provide a signature for a given sample which can be compared to known samples. The device may utilize separate channel bandwidth filters to obtain squeezed states and high S/N ratios.

Optical 3-d signature device for detecting chemical agents

A device for detecting small amounts of a chemical such as ammonia, and other ammonia-like molecules such as hydrazine or pyridine, in air and in other gases is disclosed. A capillary tube serves as a multiple total reflective medium for an optical beam from a light-emitting diode. The outer surface of the capillary tube is coated with a dye which, when exposed to the chemical, changes color so that the multiply reflected light is modified. The resultant change in the output light intensity from the capillary tube is photodetected and recorded to sense the presence of the chemical. When the chemical is removed, the dye returns to its original color so that the device can be reused.

Reversible optical waveguide vapor sensor

A method for making an airtight seal between a pair of insulator elements, uch as glass plates, without destroying any fine structure etched in the insulator elements. A thin metal film is deposited on one of the elements to be sealed and then placed in intimate contact with the other element to be sealed. The elements are then heated to a temperature well below their softening point, but high enough to significantly enhance the ion mobility in the insulator. A voltage is applied across the interface and the resulting anodic reaction consumes the film at the interface while producing a strong hermetic bond between the insulator elements.

Method for bonding insulator to insulator

A process for producing a variety of organic-inorganic luminescent and semiconductive compounds or materials in the form of a film deposited directly on the surface of a substrate by ultraviolet photoinduced condensation from gaseous reactants such as antimony pentafluoride (SbF.sub.5).sub.n and organic or inorganic halogen-containing compounds. The process provides a new class of antimony (Sb) doped luminescent and semiconductive materials which can be produced on any arbitrary size or shape substrate, or even on existing substrates of other semiconductive materials or chips, to form semiconductive devices. The process may be used in photoinducing luminescent panel displays or microelectronic circuits, such as integrated electrical or optical circuits.

Selective photoinduced condensation technique for producing

An impurity concentration profile is established in a solid by attaching solid to a heat sink and irradiating it with one or more fast laser pulses. The impurity may initially be located in a surface layer or it may be dispersed throughout the solid.

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Kensington, MD, United States of America

John F Giuliani