DURIP 09 Ultrafast Laser System for Coherent Anti-Stokes Raman Scattering Measurements at Data Rates of 5 kHz.

摘要

Funds were requested for the purchase of an ultrafast laser system and optical parametric amplifier (OPA) for nonlinear optical diagnostics in flames at data rates of 5 kHz. The ultrafast laser system as requested in the proposal system operated at 5 kHz with a pulse energy of >1.2 mJ at the fundamental wavelength of approximately 800 nm. In the time period between the submission of the DURIP proposal and the initiation of the grant, the specifications for commercial ultrafast laser systems in the price range of interest had considerably improved. A Coherent laser system with pulse energies of 2.6 mJ at 5 kHz and 1.0 mJ at 10 kHz repetition rate was purchased. The ultrafast laser system includes at 128-pixel pulse shaper to correct the phase of the laser spectrum and to ensure that the amplified laser pulses are very close to Fourier-transform-limited. An OPA and frequency-mixing system were purchased to produce a tunable beam that will be used for the pump radiation in the femtosecond coherent anti-Stokes Raman scattering (CARS) measurements. This system has been delivered and installed in the Prof. Lucht s Applied Spectroscopy Laboratory. The Coherent ultrafast laser system will be used for high-data-rate, single-pulse coherent anti-Stokes Raman scattering measurements. In addition, the use of the system for two-photon- induced fluorescence detection and measurement of species such as OH, CH, and NO will be explored. The potential for planar imaging of two-photon-induced fluorescence from these species at data rates of up to 5 kHz will be explored.