Towards quantum telescopes: demonstration of a two-photon interferometer for precision astrometry

Area of Science:

• * Astrophysics
• * Optical Interferometry
• * Quantum Optics

Background:

• * Classical optical interferometry requires costly, phase-stable links between telescope stations.
• * These links limit baseline extensions and, consequently, achievable angular resolution.
• * Extending baselines is crucial for advancing astrometric precision.

Purpose of the Study:

• * To introduce a novel two-photon interferometer for astrometry.
• * To overcome the limitations of classical optical interferometry, specifically the need for phase-stable links.
• * To enable practical, large increases in interferometric baselines for enhanced astrometric precision.

Main Methods:

• * Development of a novel two-photon interferometer design.
• * Utilization of photons from two separate sky sources, eliminating the need for inter-station optical links.
• * Testing a benchtop analogue of the two-source interferometer.

Main Results:

• * Unambiguous observation of correlated behavior in photon pair detections from two thermal light sources.
• * Experimental results align with theoretical predictions for the two-source interferometer.
• * Demonstrated feasibility of a new interferometric technique for astrometry.

Conclusions:

• * The novel two-photon interferometer technique offers a path to significantly increase interferometric baselines.
• * This advancement promises orders-of-magnitude improvements in astrometric precision.
• * Opens new possibilities for future astronomical measurements and discoveries.