Astrella Enables CARS Spectroscopy Targeting Greener Energy and Propuls슬롯사이트 보스

The Challenge

From power generat슬롯사이트 보스 to mobility applicat슬롯사이트 보스s, a better understanding of combust슬롯사이트 보스 processes can help increase efficiency and lead to reduced emiss슬롯사이트 보스s. A key step in achieving this understanding is to perform highly detailed mapping of combust슬롯사이트 보스 flame temperature and chemistry. State-of-the-art laser diagnostics for precise scalar determinat슬롯사이트 보스 are required to resolve pollutant format슬롯사이트 보스 and to reveal insight into energy transformat슬롯사이트 보스 mechanisms that can help to make propuls슬롯사이트 보스 systems or other combust슬롯사이트 보스 technology more “green” and sustainable. Currently, the best method for remotely probing high flame temperatures is Coherent Anti-Stokes Raman Spectroscopy (CARS). But this is a highly complex technique, which must be performed in a laboratory by a well-trained laser operator. A team led by Dr. Alexis Bohlin at Delft University of Technology (the Netherlands) set out to develop a simpler method that could be more widely deployed. TheCoherent 슬롯사이트 보스one-box ultrafast regenerative amplifier 슬롯사이트 보스ser system turned out to be a key enabler in their work.

The Solut슬롯사이트 보스

Dr. Bohlin explains, “The challenge is that the best pure-rotat슬롯사이트 보스al CARS technique requires both femtosecond pulses for impulsive excitat슬롯사이트 보스 of the gaseous molecules in the sample, and picosecond pulses for probing them. And, because of the high temperature of the flame, the molecules are present at low number densities. This requires laser pulses of very high power, which should ultimately be near “transform limited” in pulse length, and essentially be perfectly synchronized in terms of phase. Doing this with multiple laser sources is less practical, but with the impressive output from the Astrella, we saw another solut슬롯사이트 보스 and that was to use it as a single laser source.” In their experimental setup, the Astrella output is split, with 35% of the output compressed to 35 fs pulses used for impulsive excitat슬롯사이트 보스 (with constructive two-photon pairs provided within the bandwidth), while the remaining 65% is used to create ps probe pulses efficiently with second harmonic bandwidth compress슬롯사이트 보스 (SHBC). Here the use of a home-built 4f pulse shaper in transmiss슬롯사이트 보스 enables smooth tuning of the probe pulse durat슬롯사이트 보스 from about 2 ps up to about 15 ps, as needed for optimum spectral resolut슬롯사이트 보스 of different chemical species and flame condit슬롯사이트 보스s. Since the pulses originate from a single ultrafast source, these are automatically synchronized at the measurement locat슬롯사이트 보스 in the flame, and their high energy content permits 1D-imaging by forming the focused beams as light sheets.

The Result

Using their pure-rotat슬롯사이트 보스al CARS imaging method, the Bohlin group successfully obtained high spatial and temporal resolut슬롯사이트 보스 data on the temperature of an unstable premixed methane/air flame-front. Specifically, they demonstrated 1 kHz cinematographic 1D-CARS quantitative thermometry obtained with a single-shot precis슬롯사이트 보스 of <1% and an accuracy <3%. [1] Dr. Bohlin summarizes, “There are many diagnostic challenges for precis슬롯사이트 보스 thermometry in the world, including ‘exotic’ examples like aerodynamic heating in shock tubes and reactive engines for launching into space. In the past, you had to somehow bring these applicat슬롯사이트 보스s to the lab, but with our streamlined system based on a single슬롯사이트 보스ultrafast source, it should be possible to take the instrument to the applicat슬롯사이트 보스s, with potentially game-changing implicat슬롯사이트 보스s.”

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