An improved arctangent algorithm based on phase-locked loop for heterodyne detection system<xref rid="cpb_28_3_030701fn1" ref-type="fn">*</xref><fn id="cpb_28_3_030701fn1"><label>*</label><p>Project supported by Key Research Program of Frontier Science, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH014) and the Yong Scientists Fund of the National Natural Science Foundation of China (Grant No. 61205143).</p></fn>

An improved arctangent algorithm based on phase-locked loop for heterodyne detection system**

Project supported by Key Research Program of Frontier Science, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH014) and the Yong Scientists Fund of the National Natural Science Foundation of China (Grant No. 61205143).

Yan Chun-Hui^{1, 2}, Wang Ting-Feng^{1, †}, Li Yuan-Yang¹, Lv Tao^{1, 2}, Wu Shi-Song^{1, 2}

Demodulation results varies with the frequency error of the acousto-optic modulator Δθ; in panels (a)–(e), the accuracies of the acousto-optic modulators Δθ/θ are 1×10^–5, 8×10^–6, 4×10^–6, 2×10^–6, and 1×10^–7, respectively.