March 4, 2008Measurement Science and Technology
An absolute distance interferometer with two external cavity diode lasers
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Implication
Experimental evaluation demonstrates sub-micrometer distance measurements across two meters using dual stabilized diode lasers, highlighting viable high-precision absolute metrology for long ranges.
Key Points
- To develop and evaluate an absolute distance interferometer capable of high-precision length measurements over multi-meter ranges using two external cavity diode lasers.
- Combined a variable synthetic wavelength length measurement with a fixed synthetic wavelength interpolation (~42 µm) via modulation-free laser stabilization to Doppler-reduced rubidium absorption lines.
- Employed a stable reference interferometer as a length standard while applying linear regression to quadrature signals and correcting for mechanical vibration.
- Benchmarked the absolute interferometer against a reference counting interferometer over target distances up to 2 m.
- Demonstrated a linearity error of 0.4 µm for measurement distances up to 2 m in comparison to the counting interferometer, matching the predicted uncertainty estimation.
- Substantially lowered total measurement uncertainty by compensating for environmental vibrations and applying quadrature signal linear regression.
Cite This Study
Hartmann et al. (2008) studied this question.