Introduction Mass spectrometers are used to determine the masses of atoms, molecules, and clusters in a wide range of applications. Presently, there is a drive towards the miniaturization of such devices for use in spacecraft life support, pollution monitoring, and explosives/narcotics detection applications. For a given mass resolution, the ion flight distance (and hence the size) of a time-of-flight (TOF) mass spectrometer is related to the length of the ionization region along the flight axis. Since femtosecond pulses can ionize atoms and molecules within a very small focal volume with near unit efficiency, they are compatible with miniature mass spectrometers. We have demonstrated a general technique for compact TOF mass spectrometry using two spatially separated laser foci. The first femtosecond laser pulse ionizes a gaseous sample and the second pulse probes for the presence of a specific mass in the analyte. Our approach enables TOF mass analysis to be performed on a sub-millimetre length scale. Furthermore, the second pulse can be intense enough to explode the molecules it probes. Using such laser- induced Coulomb explosion for molecular detection yields a significant improvement in detection efficiency for large molecules. Taken together, these developments can reduce the size and complexity of miniature TOF mass spectrometers and allow the fabrication of integrated mass analyzers with relaxed voltage, vacuum, detector, and timing electronics requirements.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.