Spectral Energies, LLC, 5100 Springfield Street, Suite 301, Dayton, Ohio 45431, USA.
Opt Lett. 2011 May 15;36(10):1818-20. doi: 10.1364/OL.36.001818.
We demonstrate an all-fiber-coupled, UV, laser-induced-fluorescence (LIF) detection system of the hydroxyl radical (OH) in flames. The nanosecond-pulsed excitation of the (1,0) band of the OH A(2)∑(+)-X(2)Π system at ∼283 nm is followed by fluorescence detection from the (0,0) and (1,1) bands around 310 nm. The excitation-laser beam is delivered through a 400 μm core UV-grade optical fiber of up to 10 m in length, and the fluorescence signal collected is transmitted through a 1.5 mm core 3 m long fiber onto the remote detector. Single-laser-shot planar LIF (PLIF) imaging of OH in flames is also demonstrated using fiber-based excitation. The effects of delivering intense UV beams through long optical fibers are investigated, and the system improvements for an all-fiber-coupled OH-PLIF imaging system are discussed. Development of such fiber-based diagnostics and imaging systems constitutes a major step in transitioning laser diagnostic tools from research laboratories to reacting flow facilities of practical interest.
我们展示了一种全光纤耦合的紫外激光诱导荧光（LIF）检测系统，用于火焰中的羟基自由基（OH）检测。通过将纳秒脉冲激光激发到 OH A(2)∑(+)-X(2)Π 系统的（1,0）带，在约 283nm 处，然后在 310nm 左右检测来自（0,0）和（1,1）带的荧光。激发激光束通过长达 10m 的 400μm 芯紫外级光纤传输，收集的荧光信号通过 1.5mm 芯长 3m 的光纤传输到远程探测器。还使用基于光纤的激发演示了火焰中 OH 的单激光 shot 平面 LIF（PLIF）成像。研究了通过长光纤传输强紫外光束的影响，并讨论了用于全光纤耦合 OH-PLIF 成像系统的系统改进。这种基于光纤的诊断和成像系统的发展是将激光诊断工具从研究实验室过渡到实际应用的反应流设备的重要一步。
