Laser Sensors and Diagnostics

SRI's Laser Sensors and Diagnostics group provides government and commercial clients with fundamental and applied research in areas involving laser sensors and diagnostics, mass spectroscopy,and chemical modeling with a broad range of potential applications. Together with the Molecular Physics Group, we operate the REU Program. Our team's experience includes:

• Atmospheric Chemistry: Chemical kinetics, modeling, high temperature air chemistry
• Atomic, Molecular and Optical Physics: Small molecular spectroscopy, collisional energy transfer, laser scattering, medical diagnostics
• Combustion: Flame diagnostic methods, optical sensor, combustion chemistry models, flame emission in microgravity
• Mass Spectroscopy: Single-particle composition, metal impurities in silicon, surface analysis, combinatorial chemistry
• Trace species monitoring: Jet-REMPI continuous emission monitor, speciated Hg, toxic metals, dioxin detection

Innovative Technologies

• Surface Analysis by Laser Ionization (SALI): Laser-based method of analyzing less than a surface monolayer
• Gas Chromatography/Field Ionization Mass Spectroscopy (GC-FIMS): A combination of gas chromatography with a very soft, nonfragmenting ionization technology for a mass spectrometer, allowing rapid identification of complex mixtures of hydrocarbons including crude oils or fuels
• Molecular Upconverters: Molecular-sized (not particle-sized) reporters based on rare-earth ion chelates that produce visible light when illuminated by infrared lasers
• Phosphor Upconverters: Rare earth ions imbedded in small particles that can be used for a variety of sensing technologies
• Jet-REMPI: A combination of three technologies, supersonic nozzles, resonant laser ionization, and time of flight mass spectrometry to provide unparalleled sensitivity and selectivity

Facilities

• Jet-REMPI Apparatus: Capable of sub-part-per-billion detection of hazardous air pollutants, plan to start a fieldable version in early 2000.
• Diamond Film Facility: A research version of a commerically useful arc-jet device for producing diamond films on suitable substrates. Can be probed using laser techniques.
• Low Pressure Burners: Premixed burners that support hydrocarbon/air flames to 30 Torr. Used for highly spatially resolved laser measurements of flame intermediates to test flame chemistry.
• Single Particle Mass Spectrometer: A unique device for measuring the chemical composition of single particles in the atmosphere. Has flown on NASA's DC-8 in tropospheric missions and been used on the ground.
• SALI: Laser-based surface analysis, commercially available and important in other projects.
• Fluorescence Marking: A new technology based on fast laser pulsing, that provides marking within, not just upon, items.
• Speciated Mercury Detection: Device for continuous monitoring of the toxic metal mercury, distinguishing among three forms: aseous elemental, gaseous chemically bound, and particulate.
• Optical Combs: A multiplexing technology providing thousands of waveforms in a small bandwidth. Useful for encrypting messages.
• Laser-Secondary Neutral Mass Spectroscopy: A variant of SALI for detecting small amounts of metal impurities (<10⁹/cm³) on Si wafers, with higher potential sensitivity for meeting industry needs in years.

List of relevant publications.

Contact Us:

For more information about SRI's Laser Sensors & Diagnostics,
how to work with our team and put our innovations to work, contact
David R. Crosley
650-859-2395
david.crosley@sri.com