Experimental study of mid-IR laser beam wander close to a jet engine exhaust
Experimental study of mid-IR laser beam wander close to a jet engine exhaust
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中红外激光束在喷气发动机排气附近漂移的实验研究
DOI：
10.1117/12.689638
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发表时间：
2006
影响因子：
--
通讯作者：
O. Gustafsson
中科院分区：
文献类型：
--
作者：
M. Henriksson;L. Sjöqvist;O. Gustafsson
激光器放置在飞机上的主动对抗和主动成像的兴趣越来越大。关于喷气发动机排气附近的传播效应以及用自适应光学补偿它们的可能性，仍然存在未解决的问题。在小型喷气发动机试验台上进行了平行于排气的激光束传输实验。实验用1.6和3.5 μm波长的纳秒激光脉冲进行。将激光光斑投影到屏幕上，并通过摄像机对质心运动进行成像。对于不同的发动机条件和几何形状，观察到束流漂移的均方根幅度在50和150 μrad之间。3.5 μm系统的帧频为607 Hz，可以部分解决光束漂移的时间变化。观察到光束漂移的相关时间（50%）为3.5 ms。当发动机启动时，由于温度和压力的平均梯度，还发现了几百μrad的偏转。
An increasing interest in lasers placed on aircrafts for active countermeasures and active imaging is observed. There remain unsolved issues regarding the propagation effects close to the jet engine exhaust and the possibilities of compensating them with adaptive optics. Laser beam propagation experiments parallel to the exhaust of a downscaled jet engine test rig have been performed. The experiments were carried out with nanosecond laser pulses at 1.6 and 3.5 μm wavelength. The laser spots were projected on a screen and the centroid motion were imaged by cameras. Root mean square magnitudes of the beam wander between 50 and 150 μrad were observed for different engine conditions and geometries. The 3.5 μm system had a frame rate of 607 Hz and could partly resolve the time variation of the beam wander. A correlation time (50 %) of 3.5 ms was observed for the beam wander. Deflections of several hundred μrad due to the average gradients in temperature and pressure were also found when the engine was turned on. In addition to beam wander intensity scintillations has been studied.