Temperature-fluctuation-sensitive accumulative effect of the phase measurement errors in low-coherence interferometry...

Area of Science:

• Optical Engineering
• Metrology
• Interferometry

Background:

• Low-coherence interferometry is crucial for characterizing optical multipath components.
• Environmental temperature fluctuations can introduce phase measurement errors due to refractive index variations.
• These errors can accumulate, impacting the accuracy of optical component characterization.

Purpose of the Study:

• To investigate the accumulative effect of phase measurement errors in low-coherence interferometry.
• To understand the influence of environmental temperature fluctuations on these errors.
• To identify methods for mitigating the accumulative phase measurement errors.

Main Methods:

• Utilized low-coherence interferometry to measure optical multipath components.
• Experimentally induced and monitored phase measurement errors under varying environmental conditions.
• Varied scanning speed during measurements to assess its impact on error accumulation.

Main Results:

• Demonstrated that phase measurement errors accumulate with increasing phase difference between interferometer arms.
• Confirmed that the accumulative effect is significant even with small thermo-optical coefficients.
• Observed a substantial decrease in the slope of phase measurement errors with increased scanning speed (up to 4.8 mm/s).

Conclusions:

• Environmental temperature fluctuations are a primary cause of accumulative phase measurement errors.
• Increasing the scanning speed of the interferometer is an effective method to suppress these errors.
• At a scanning speed of 4.8 mm/s, the accumulative effect becomes negligible, enabling accurate characterization.