Orthogonal CORDIC-based rotation phase interrogation for EFPI Fabry-Perot sensor

In response to the growing demand for high real-time F-P demodulation algorithms, we present what we believe to be a novel Hilbert orthogonal F-P demodulation algorithm, HT-CORDIC, which is based on the Coordinate Rotation Digital Computer (CORDIC) algorithm. HT-CORDIC aims to balance accuracy and real-time performance. The algorithm employs the Hilbert transform to identify orthogonal signals, determines a specific phase difference through the Givens transform, and then extracts the cavity length through the vector of the CORDIC algorithm. The algorithm was evaluated through a series of demodulation simulations and experiments conducted on the EFPI sensors. The results demonstrate that the demodulation accuracy is approximately 1 nm at a cavity length of 192.395µm. Furthermore, the algorithm demonstrates an exceptionally high degree of linearity, with an R 2 value of 0.9999. The parallel structure algorithm has been demonstrated to reduce the time required for demodulation in comparison to the traditional cross-correlation method. Furthermore, the resolution was found to be satisfactory, at 2.23 nm, with an average of 0.2533 nm for the algorithmic noise MSE. It can be concluded that the HT-CORDIC algorithm has the potential to be employed for high-real-time F-P interferometric demodulation.