10  kHz two-color OH PLIF thermometry using a single burst-mode OPO

• Published in: Optics letters 2021-05, Vol.46 (10), p.2308-2311
• Main Authors: Hsu, Paul S, Jiang, Naibo, Felver, Josef J, Lauriola, Daniel K, Danehy, Paul M, Roy, Sukesh
• Format: Article
• Language: English
• ISSN: 0146-9592; 1539-4794
• DOI: 10.1364/OL.423062

10-kHz hydroxyl radical (OH) two-color planar laser-induced fluorescence (TC-PLIF) thermometry was demonstrated with a single burst-mode optical parametric oscillator (OPO) and a single camera. A fast, dual-wavelength switched seed laser enabled a high-energy, high-repetition-rate burst-mode laser to generate two 10-kHz pulse trains at wavelengths of ${\sim}{354.8}\;{\rm nm}$. The two pulse trains are colinear with 3 µs time interval between the pulse pairs. The injection-seeded OPO efficiently converts the burst-mode laser output to 285.62 and 285.67 nm to excite the ${Q}_2({12})$ and ${P}_1({8})$ OH transitions. PLIF images were collected from each of the two excitation transitions, and intensity ratios from the images were used to determine local temperatures. The development of fast, dual-wavelength switching, burst-mode OPO technology significantly reduces the experimental complexity of the high-speed TC-PLIF thermometry and simplifies its implementation in harsh combustion and flow test facilities.