Development of a broadband picosecond infrared spectrometer and its incorporation into an existing ultrafast time-resolved resonance Raman, UV/visible, and fluorescence spectroscopic apparatus

Appl Spectrosc. 2003 Apr;57(4):367-80. doi: 10.1366/00037020360625899.

Abstract

We have constructed a broadband ultrafast time-resolved infrared (TRIR) spectrometer and incorporated it into our existing time-resolved spectroscopy apparatus, thus creating a single instrument capable of performing the complementary techniques of femto-/picosecond time-resolved resonance Raman (TR3), fluorescence, and UV/visible/infrared transient absorption spectroscopy. The TRIR spectrometer employs broadband (150 fs, approximately 150 cm(-1) FWHM) mid-infrared probe and reference pulses (generated by difference frequency mixing of near-infrared pulses in type I AgGaS2), which are dispersed over two 64-element linear infrared array detectors (HgCdTe). These are coupled via custom-built data acquisition electronics to a personal computer for data processing. This data acquisition system performs signal handling on a shot-by-shot basis at the 1 kHz repetition rate of the pulsed laser system. The combination of real-time signal processing and the ability to normalize each probe and reference pulse has enabled us to achieve a high sensitivity on the order of deltaOD approximately 10(-4) - 10(-5) with 1 min of acquisition time. We present preliminary picosecond TRIR studies using this spectrometer and also demonstrate how a combination of TRIR and TR3 spectroscopy can provide key information for the full elucidation of a photochemical process.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA / chemistry
  • Equipment Design
  • Equipment Failure Analysis
  • Molecular Probes
  • Photochemistry / instrumentation
  • Photochemistry / methods
  • Quality Control
  • Signal Processing, Computer-Assisted*
  • Spectrometry, Fluorescence / instrumentation*
  • Spectrometry, Fluorescence / methods
  • Spectrophotometry, Infrared / instrumentation*
  • Spectrophotometry, Infrared / methods
  • Spectrophotometry, Ultraviolet / instrumentation*
  • Spectrophotometry, Ultraviolet / methods
  • Spectrum Analysis, Raman / instrumentation*
  • Spectrum Analysis, Raman / methods
  • Systems Integration

Substances

  • Molecular Probes
  • DNA