California Institute of Technology

Dmitri A Kossakovski

Marc Alexander Unger

John D Baldeschwieler

Jesse L Beauchamp

Stephen D O'Connor

Gregory H Bearman

Adrian Ponce

Marcel Widmer

Optical time domain reflectometry caused by absorption of a volatile or analyte into the fiber optic cladding is used an optical nose. The fiber optics () are covered with a gas permeable film () which is patterned to leave millimeter wide gas permeable notches (-). The notches contain a sensing polymer that responds to different gases by expanding or contracting.

Method and apparatus for distributed sensing of volatiles using a long period fiber grating sensor with modulated plastic coating for environmental monitoring

A scanning probe microscope is combined with a laser induced breakdown spectrometer to provide spatially resolved chemical analysis of the surface correlated with the surface topography. Topographical analysis is achieved by scanning a sharp probe across the sample at constant distance from the surface. Chemical analysis is achieved by the means of laser induced breakdown spectroscopy by delivering pulsed laser radiation to the sample surface through the same sharp probe, and consequent collection and analysis of emission spectra from plasma generated on the sample by the laser radiation. The method comprises performing microtopographical analysis of the sample with a scanning probe, selecting a scanned topological site on the sample, generating a plasma plume at the selected scanned topological site, and measuring a spectrum of optical emission from the plasma at the selected scanned topological site. The apparatus comprises a scanning probe, a pulsed laser optically coupled to the probe, an optical spectrometer, and a controller coupled to the scanner, laser and spectrometer for controlling the operation of the scanner, laser and spectrometer. The probe and scanner are used for topographical profiling the sample. The probe is also used for laser radiation delivery to the sample for generating a plasma plume from the sample. Optical emission from the plasma plume is collected and delivered to the optical spectrometer so that analysis of emission spectrum by the optical spectrometer allows for identification of chemical composition of the sample at user selected sites.

Method and apparatus for chemical and topographical microanalysis

A two-phase etching system having an etchant solution and an overlayer of a protective solvent. The physical properties of the etchant solution and the protective solvent are matched to form a flat meniscus on the top surface of the etchant solution around a fiber immersed in the protective solvent and the etchant solution. Convective flows within the etchant solution are maintained in order to form a smooth and sharp fiber probe with a small tip apex.

Device for chemically etching a fiber probe

The present invention discloses an improved method and apparatus for analyzing the surface of materials using sub-micron laser desorption gas phase analysis. The method uses a combination of Near-field Optical Microscopy and Time-of Flight Mass Spectroscopy.

Sub-micron chemical imaging with near-field laser desorption

A two-phase etching system having an etchant solution and an overlayer of a protective solvent. The physical properties of the etchant solution and the protective solvent are matched to form a substantially flat meniscus on the top surface of the etchant solution around a fiber immersed in the protective solvent and the etchant solution. Convective flows within the etchant solution are maintained to form a smooth and sharp fiber probe with a small tip apex.

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Pasadena, CA, United States of America

Dmitri A Kossakovski