Principles of Interferometry

Cláus Lämmerzahl

The role of the equivalence principle in the context of non-relativistic quantum mechanics and matter wave interferometry, especially atom beam interferometry, will be discussed. A generalised form of the weak equivalence principle which is capable of covering quantum phenomena too, will be proposed. It is shown that this generalised equivalence principle is valid for matter wave interferometry and for the dynamics of expectation values. In addition, the use of this equivalence principle makes it possible to determine the structure of the interaction of quantum systems with gravitational and inertial fields. It is also shown that the path of the mean value of the position operator in the case of gravitational interaction does fulfill this generalised equivalence principle.

Bernard F. Burke, F. G. Smith, Peter N. Wilkinson

Nikolai A. Ushakov, Маркварт Александр Александрович, Лиокумович Леонид Борисович

The paper proposes a spectral-domain version of a biphoton (Hong–Ou–Mandel) interferometry. The operation principle is based on measuring the coincidence rate of entangled photons while scanning the difference between their central frequencies. A theoretical apparatus describing the operation principle and the resolution limits of the proposed spectral-domain biphoton interferometry is developed. The analysis is based on quantum and classical Cramer–Rao bounds. It was shown that the proposed spectral-domain biphoton interferometry approach enables the mitigation of the fringe number counting errors, often encountered in classical spectral interferometry. A comparison with a conventional Hong–Ou–Mandel biphoton interferometry is also presented.

A. F. Boden

Jinglei Chen

With over 20 years of development, atomic interferometry gravimeters have distinguished themselves in gravity measurements by their high precision and sensitivity. To cater to the demands of field absolute gravity measurements for marine and aerial gravity field measurements, resource exploration, inertial navigation, and positioning, the miniaturization, mobility, and engineering of atomic interferometry gravimeters have become crucial areas of development. On this basis, this article elucidates the principles of atomic interferometry gravimeters, encompassing various laser cooling techniques, magneto-optical traps, and Raman light interference. As a matter of fact, it provides an overview of the principles and achieved precision benchmarks of portable, vehicular, airborne, and shipborne atomic interferometry gravimeters. Additionally, it analyzes the experimental content and results of maritime, terrestrial, and aerial experiments based on portable atomic interferometry gravimeters. The limitations of portable atomic interferometry gravimeters are discussed, along with an exploration of their application prospects. Overall, these results shed light on guiding further exploration of mobile atom interferometry gravity.

Ángel S. Sanz, Salvador Miret-Artés