The design, optimization and demonstration of a compact, single-ended laser absorption sensor based on a diffuse-wall-reflected signal is presented for temperature and H 2 O concentration measurements in a kerosene-fuelled aero-combustor. The challenges of laser measurements in such harsh, practical combustion environments involve strong beam-steering, low signal-to-noise ratio (SNR), and constrained optical access. We present here a detailed characterization and optimization procedure of a single-ended optical configuration using a holed off-axis parabolic mirror as the pitch and catch optics, and the coked wall surface of the combustor as a diffuse reflector. A near-infrared distributed-feedback diode laser near 1.4 µm scanned at 1 kHz for direct absorption detection was used to access two H 2 O transitions for concentration and temperature measurement. An optical system design and adaptive Savitzky–Golay signal processing algorithm were used for noise suppre...

中文翻译：

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基于扩散反射的单端激光吸收传感器，用于煤油燃料燃烧室中的H 2 O温度和浓度

提出了一种基于扩散壁反射信号的紧凑型单端激光吸收传感器的设计，优化和演示，用于在煤油供油的空气燃烧器中进行温度和H 2 O浓度测量。在如此恶劣，实际的燃烧环境中，激光测量面临的挑战包括强大的光束转向，低信噪比（SNR）和受限的光学通道。我们在此介绍单端光学配置的详细表征和优化过程，该配置使用带孔的离轴抛物面镜作为俯仰和捕获光学器件，而燃烧室的焦化壁表面作为漫反射镜。1附近的近红外分布式反馈二极管激光器。以1 kHz扫描4 µm进行直接吸收检测，以访问两个H 2 O跃迁进行浓度和温度测量。光学系统设计和自适应Savitzky-Golay信号处理算法用于噪声抑制。