Authors
Julien Vaillant, Aurelien Bruyant,
Title
An unbalanced interferometer insensitive to wavelength drift
In
Sensors and Actuators A: Physical
Volume
268
Pages
188–192
Publisher
Elsevier
Year
2017
Publisher's URL
https://doi.org/10.1016/j.sna.2017.10.022
Indexed by
Abstract
Frequency-modulated interferometry offers a unique way to create phase modulation in 2-arm interferometers with a small footprint and cost. However, this approach is not widely used in common interferometric devices due to its sensitivity to small wavelength fluctuations and the difficulty to handle intricated phase and amplitude modulation. In this paper, we tackle these issues by performing unbalanced interferometry immune to laser wavelength fluctuations via a slightly modified setup comprising an unstabilized laser source and an additional reference arm. High performances are obtained with minimal equipment by using a power modulated VCSEL and the “generalized lock-in amplifier” method: the slow phase drift due to temperature change is efficiently canceled out while the high frequency noise is divided by a factor of 2.4. The measurement of slow displacement (0.1–10 Hz) with a sub-nanometric …
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