Optical, Opto-Atomic, and Entanglement-Enhanced Precision Metrology II

A. P. Alodjants, Dmitriy V. Tsarev, Dmitry Kuts +2 more

Andrea Crespi, Mirko Lobino, Jonathan C. F. Matthews +5 more

Optical interferometry is amongst the most sensitive techniques for precision measurement. By increasing the light intensity, a more precise measurement can usually be made. However, if the sample is light sensitive entangled states can achieve the same precision with less exposure. This concept has been demonstrated in measurements of known optical components. Here, we use two-photon entangled states to measure the concentration of a blood protein in an aqueous buffer solution. We use an opto-fluidic device that couples a waveguide interferometer with a microfluidic channel. These results point the way to practical applications of quantum metrology to light-sensitive samples.

A. P. Alodjants, Dmitriy V. Tsarev, Dmitry Kuts +2 more

Junwen Luo, Dewei Wu, Qiang Miao +2 more

Microwave is widely used in present navigation system. It works well, yet it faces precision limit and other challenges. Quantum entanglement has been applied in various fields and resulted in quite remarkable improvements, especially in precision performance. Hence, we attempt to apply quantum entanglement to enhance merits of navigation system performed in microwave regime. This paper introduces principles of microwave-optical entanglement prepared by electro-opto-mechanical converters in detail. Meanwhile, a navigation ranging scheme exploiting this type of entanglement is proposed. The performance of the scheme is analyzed, and factors influencing entanglement feature and ranging feature are discussed. It shows that the ranging scheme has achieved quite precise results with help of microwave-optical entanglement, and it may be regarded as a promising candidate of new navigation ranging scheme.

Polzik

Matthew A. Norcia

Abstract Narrow linewidth optical atomic transitions provide a valuable resource for frequency metrology, and form the basis of today's most precise and accurate clocks. Recent experiments have demonstrated that ensembles of atoms can be interfaced with the mode of an optical cavity using such transitions, and that atom-cavity interactions can dominate over decoherence processes even when the atomic transition that mediates the interactions is very weak. This scenario enables new opportunities for optical frequency metrology, including techniques for nondestructive readout and entanglement enhancement for optical lattice clocks, methods for cavity-enhanced laser frequency stabilization, and high-precision active optical frequency references based on superradiant emission. This tutorial provides a pedagogical description of the physics governing atom-cavity coupling with narrow linewidth optical transitions, and describes several examples of applications to optical frequency metrology.