Combining sub-Nyquist sampling and chirp decomposition for a high-precision and speed absolute distance measurement...

Area of Science:

• Optical Metrology
• Precision Measurement Engineering

Background:

• Absolute distance measurement is crucial in various scientific and industrial applications.
• Swept-wavelength interferometry (SWI) offers high resolution but faces challenges with speed and dispersion.
• Existing methods for dispersion compensation can be time-consuming or less accurate.

Purpose of the Study:

• To develop a high-precision and high-speed absolute distance measurement technique.
• To propose an effective method for dispersion mismatch compensation in SWI.
• To improve the accuracy and reduce the measurement time compared to traditional approaches.

Main Methods:

• Utilizing swept-wavelength interferometry (SWI) for absolute distance determination.
• Implementing a novel approach combining sub-Nyquist sampling and chirp decomposition for dispersion compensation.
• Analyzing measurement performance against traditional methods.

Main Results:

• Achieved a standard deviation of 0.72 μm for a 3.9 m distance measurement, surpassing traditional methods.
• Demonstrated a measurement completion time of 1.9 s over a 4.26 THz frequency range.
• Showcased the superiority of the combined sub-Nyquist sampling and chirp decomposition technique.

Conclusions:

• The proposed SWI method offers a significant advancement in high-precision and high-speed absolute distance measurement.
• Sub-Nyquist sampling combined with chirp decomposition provides an effective solution for dispersion mismatch compensation.
• This technique presents a more efficient and accurate alternative for demanding metrology applications.