Portable CARS System

Spectral Energies’ mobile PS-CARS system provides the benefits of non-intrusive, accurate measurements of temperature and species concentrations available to combustors, gas-turbine engines, and other harsh optical environments. The PS-CARS system is compact, easy-to-use, mobile and provides high-spatial resolution temperature measurements. This system allows for the suppression of nonresonant-background (NRB) interference signal by time-delaying the probe pulse with respect to the pump/Stokes pulses, thereby improving the accuracy and sensitivity of CARS thermometry, a feature particularly useful in rich hydrocarbon-air flames [T.R. Meyer, S. Roy, and J. R. Gord, Appl. Spectros. 61, 1135 (2007)].].


- Full system is housed on a small cart for easy mobility.

- The use of short ps pulse allows for the:

  • Suppression of nonresonant background to improve measurement accuracy
  • Achievement of high pulse intensity resulting in high signal-to-noise(SNR) CARS spectra
  • Reduction of the required laser energy for CARS measurements, avoiding costly window damage in optical combustors
  • Investigation of the collisional and Doppler dependence of signal through time-resolved measurements [Kulatilaka et al. Appl. Phys. Lett. 97, 081112 (2010)].


Pump & Probe beam (532.2 nm)
Energy:~10 mJ/pulse
Pulse width: ~100 ps
Bandwidth: ~0.2 cm-1
Beam quality: M2<1.2

Stokes beam (~607 nm)
Energy:3 mJ/pulse
Pulse width: ~100 ps
Bandwidth: ~135 cm-1
Beam quality: M2~1.8