Ambient light (AML) limits the usage of absorption spectroscopy to strictly-controlled environments due to its impact on the quality of the signals. In medical applications for Optical instruments that require high reliability and validity results, it is indispensable to control AML impact. In this work, we present a multi-wavelength optical acquisition method, here called SHADE. The technique increases the quality of the optical signals, dynamically assesses AML, and enables mitigating the AML influence on the data. Our proposed technique involves four primary functions: (1) Multiplexing/demultiplexing of target wavelengths using a frequency-division method; (2) Robust signal recovery using inverse notch filters; (3) Concurrent AML intensity estimation; (4) A simple post-processing (offline) suppression of AML interference. We introduce the mathematical framework of SHADE to demonstrate the theoretical scope and limitations. SHADE was also experimentally tested by using a digital signal processing board under different conditions. The results confirmed the performance of the AML reconstruction and the potential of such a method for further improvements of the signal quality.

环境光（AML）由于会影响信号质量，因此将吸收光谱的使用限制在严格受控的环境中。在要求高可靠性和有效性结果的光学仪器的医疗应用中，控制AML影响必不可少。在这项工作中，我们提出了一种多波长光学采集方法，这里称为SHADE。该技术提高了光信号的质量，可以动态评估AML，并可以减轻AML对数据的影响。我们提出的技术涉及四个主要功能：（1）使用分频方法对目标波长进行复用/解复用；（2）使用反向陷波滤波器进行稳健的信号恢复；（3）并发AML强度估计；（4）对AML干扰的简单后处理（离线）抑制。我们介绍SHADE的数学框架，以证明理论范围和局限性。SHADE还通过使用数字信号处理板在不同条件下进行了实验测试。结果证实了AML重建的性能以及这种方法用于进一步改善信号质量的潜力。