Presentation Information
[9p-P03-29]Absolute Distance Measurement Based on Three-Wavelength Interferometry
〇(M2)Yile Nan1, Naoki Yamaguchi1, Takaki Kiyozumi1, Hayato Yoshimura1, Sze Yun Set2, Shinji Yamashita1 (1.Tokyo Univ., 2.RCAST, Tokyo Univ.)
Keywords:
Multi-Wavelength Interferometric Method,Multi-Wavelength Interferometer,Absolute Distance
This research presents an absolute distance measurement method based on three-wavelength interferometry combined with a dithering technique. Compared to conventional single-wavelength interferometry, which is limited to a measurement range of one wavelength, the proposed approach achieves both high accuracy and an extended unambiguous range by synthesizing multiple wavelengths. Intermediate synthetic wavelengths are calculated using phase differences, and a final long synthetic wavelength is derived from these. To resolve the phase ambiguity inherent in sinusoidal signals, a dithering technique is introduced, enabling precise phase determination by analyzing waveform trends within the dithering region. In the experiment, light at three wavelengths (1560.695 nm, 1562.983 nm, and 1565.717 nm) was generated and injected into the interferometric system via an SOA. Based on the amplitude and midpoint of the dithering waveform, an absolute distance of 4.49 cm was successfully reconstructed from the dithered signal, demonstrating the effectiveness of the method.