Optical Frequency Comb Frequency-division Multiplexing Dispersive Interference Multichannel Distance Measurement

An optical frequency comb (OFC) frequency-division multiplexing dispersive interference multichannel distance measurement method is proposed. Based on the OFC dispersive interference, the wide OFC spectrum is divided into multiple channels using a wavelength-division multiplexer. Under the existing light source and spectrometer, a single interference system can realize six channels of the high-precision parallel absolute distance measurement. The influence of the spectrum width and shape on the performance of the distance measurement channel is analyzed. The ranging accuracy of six channels is higher than +/- 4 mu m under the optimization of a nonuniform discrete Fourier transform and Hanning window. Multichannel parallel ranging is realized by combining the width spectral characteristics of femtosecond optical comb with frequency-division multiplexing technologyNon-uniform Fourier transform algorithm is used to improve the nonlinear error of optical frequency sampling of spectrometer and optimize the absolute ranging accuracyThe multichannel parallel ranging system has the potential of industrial field traceability, providing a reference for large-scale spatial measurement and multi-dimensional geometry measurement.