Continuous dynamic measurement of frequency scanning interferometry based on motion phase synchronization...

Area of Science:

• Metrology and Measurement Science
• Optical Physics
• Instrumentation Engineering

Background:

• Dynamic absolute distance measurement (DADM) is crucial in various scientific and industrial applications.
• Existing frequency scanning interferometry (FSI) methods face challenges with Doppler effect errors and optical frequency deviations.
• Accurate real-time compensation for target motion and laser frequency instability is essential for high-precision measurements.

Purpose of the Study:

• To develop a continuous dynamic frequency scanning interferometry (DFSI) measurement method that suppresses distance errors caused by the Doppler effect.
• To analyze the impact of optical frequency deviation (OFD) from tunable and heterodyne interferometry (HI) lasers on DADM accuracy.
• To propose and validate an online optical frequency measurement technique for enhancing DFSI precision.

Main Methods:

• Integration of heterodyne interferometry (HI) synchronization measurement with FSI motion phase compensation.
• Analysis of the influence of initial optical frequency deviation (OFD) on DADM and target motion parameters.
• Implementation of an online optical frequency measurement method using HI and H¹³C¹⁴N gas absorption cells for calibration.

Main Results:

• The proposed DFSI method effectively suppresses distance errors introduced by the Doppler effect.
• Optical frequency deviation was identified as the fundamental cause of accuracy degradation in DFSI.
• Online calibration of laser optical frequencies and motion phase compensation enabled highly accurate continuous DADM.

Conclusions:

• The developed DFSI method with motion phase synchronization compensation and calibration significantly improves measurement accuracy.
• Online optical frequency measurement is critical for mitigating errors in dynamic absolute distance measurements.
• The validated method achieves highly accurate and continuous dynamic absolute distance measurement, suitable for demanding applications.