Wavelength-agile diode-laser sensing strategies for monitoring gas properties in optically harsh flows: application in cesium-seeded pulse detonation.
Wavelength-agile diode-laser sensing strategies for monitoring gas properties in optically harsh flows: application in cesium-seeded pulse detonation.
复制标题
用于监测光学恶劣流中气体特性的波长捷变二极管激光传感策略：在铯种子脉冲爆炸中的应用。
作者：
S. Sanders;D. Mattison;Lin Ma;J. Jeffries;R. Hanson
先进的二极管激光器的快速、宽波长扫描能力允许将传统的二极管激光吸收技术扩展到高压、瞬变和通常恶劣的环境。在这里，我们通过应用垂直腔面发射激光器(VCSEL)来监测脉冲爆震发动机(PDE)中的气体温度和压力来演示这一扩展。使用积极的注入电流调制，VCSEL以兆赫的速率扫描通过10厘米-1的光谱窗口-大约是传统半导体激光器扫描范围的10倍和扫描速率的1000倍。VCSEL探测~5ppm的~5ppm的Cs原子在PDE的原料气体中的~852 nm D2跃迁的吸收线型。利用这些线型，分别记录了2000-4000K和0.5-30atm范围内的爆轰气体温度和压力的微秒时间响应历史。波长捷变半导体激光器的可用性不断提高，应该有助于开发用于其他恶劣流动的类似传感器，使用其他吸波材料，如天然水。
The rapid, broad wavelength scanning capabilities of advanced diode lasers allow extension of traditional diode-laser absorption techniques to high pressure, transient, and generally hostile environments. Here, we demonstrate this extension by applying a vertical cavity surface-emitting laser (VCSEL) to monitor gas temperature and pressure in a pulse detonation engine (PDE). Using aggressive injection current modulation, the VCSEL is scanned through a 10 cm-1 spectral window at megahertz rates - roughly 10 times the scanning range and 1000 times the scanning rate of a conventional diode laser. The VCSEL probes absorption lineshapes of the ~ 852 nm D2 transition of atomic Cs, seeded at ~ 5 ppm into the feedstock gases of a PDE. Using these lineshapes, detonated-gas temperature and pressure histories, spanning 2000 - 4000 K and 0.5 - 30 atm, respectively, are recorded with microsecond time response. The increasing availability of wavelength-agile diode lasers should support the development of similar sensors for other harsh flows, using other absorbers such as native H2O.