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Updated: Feb 15, 2026
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The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
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Phase stabilization for long-baseline interferometry of incoherent optical sources
Optics Letters
|February 13, 2026
Summary
Astronomical interferometers can now achieve longer baselines using off-band phase stabilization over 170 km fiber optic links. This technique significantly reduces phase noise, enabling enhanced resolution for optical and quantum astronomy.
Area of Science:
- Astronomy and Astrophysics
- Optical Engineering
- Quantum Optics
Background:
- Optical astronomical interferometers face limitations in baseline length and resolution due to phase noise and optical path attenuation.
- Existing optical delay lines are practically limited to a few hundred meters, restricting interferometer scale.
Purpose of the Study:
- To implement and validate off-band phase stabilization for extending the baseline of optical interferometers.
- To demonstrate the effectiveness of phase stabilization in reducing phase noise over long fiber optic links.
- To assess the impact of phase stabilization on recovering photon correlations in an interferometer.
Main Methods:
- Utilized two fiber optic links, each 85 km long, to create a total baseline of 170 km.
- Implemented off-band phase stabilization techniques to manage phase noise in the optical path.
- Employed an incoherent pseudo-thermal source with an 11.2 nm bandwidth for testing.
Main Results:
- Successfully phase stabilized signals over the 170 km baseline, reducing phase noise by 4-5 orders of magnitude (1-100 Hz).
- Achieved resolution of an applied phase difference of 0.16 cycles per second with continuous measurement.
- Demonstrated the recovery of both first-order and second-order photon correlations with active phase stabilization.
Conclusions:
- Off-band phase stabilization is a feasible technique for constructing long-baseline optical and quantum astronomical interferometers.
- The developed method significantly enhances the phase stability required for high-resolution astronomical observations.
- Chromatic dispersion in fiber optics is a limiting factor, but can be addressed with dispersion-compensating modules.
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