Research on Dual-Grating Spacing Calibration Method Based on Multiple Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise Combined with Hilbert Transform

• Published in: Photonics Vol. 11; no. 5; p. 443
• Main Authors: Zhu, Yanzhen, Sun, Jiayuan, Guan, Yuqing, Liu, Liqin, Guo, Chuangwei, Zhang, Yujie, Wan, Jun, Lei, Lihua
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2024
• Subjects: Accuracy; Algorithms; Atomic Force Microscopy (AFM); Calibration; Decomposition; Entropy; Fourier transforms; grating spacing calibration; Hilbert transformation; homodyne interference; Lasers; Methods; Phase unwrapping; planar grating; signal decomposition; Signal processing; Signal reconstruction; Vibration
• ISSN: 2304-6732; 2304-6732
• DOI: 10.3390/photonics11050443

The paper proposes a method for the calibration of spacing in dual-grating based on Multiple Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (ICEEMDAN) combined with Hilbert Transform (HT), referred to as Multiple ICEEMDAN-HT. This method addresses the potential impact of nonlinear factors on phase extraction accuracy, consequently on ranging precision in the homodyne interference of the dual-grating. Building upon the ICEEMDAN algorithm, the signal undergoes iterative decomposition and reconstruction using the sample entropy criterion. The intrinsic mode functions (IMFs) obtained from multiple iterations are then reconstructed to obtain the complete signal. Through a simulation and comparison with other signal decomposition methods, the repeatability and completeness of signal reconstruction by Multiple ICEEMDAN are verified. Finally, an actual dual-grating ranging system is utilized to calibrate the spacing of the planar grating. Experimental results demonstrate that the calibration relative error of the Multiple ICEEMDAN-HT phase unwrapping method can be reduced to as low as 0.07%, effectively enhancing the signal robustness and spacing calibration precision.