Key metrologies/systems: Near-infrared (IR) supercontinuum light sources/long-path absorbance Fourier transform IR spectrometry. Advanced platforms and protocols are being developed towards innovative broadband spectroscopies in the near-infrared with applications ranging from stand-off detection of trace-level atmospheric constituents to chemical imaging microscopy
Fourier Transform Spectrometry with a Near Infrared Supercontinuum Source
Optical fiber based supercontinuum (SC) light sources combine the brightness of lasers with the bandwidth of incandescent lamps and thus are promising cnadidates for sources in spectroscopic applications requiring high brightness and broad bandwidth. Near-infrared Fourier transform spectrometry with an SC light source has been demonstrated for long path absorption spectroscopy of trace gas species. Spectra of these trace gases illustrate the advantage the SC source has over traditional incandescent sources in that it can propogate in a collimated fashion over long distances, thus providing a sensitivity advantage. The spectra also demonstrate the disadvantage of the SC source with respect to the lamp in the increased level of amplitude noise.
Broadband Coherent anti-Stokes Raman Spectroscopy Characterization of Polymer Thin Films
Coherent anti-Stokes Raman Scattering (CARS) is a high sensitivity alternative to conventional Raman spectroscopy. Ultrafast lasers have been used to enable multiplex CARS spectroscopy with a clear sensitivity advantages over conventional Raman spectroscopy for the characterization of thin films. The spectroscopy shows special promise for the characterization of the ultrathin organic films required for advanced electronic applications such as organic light emitting diodes and thin film transistors.