Despite well-established no-go theorems on a perfect linear optical Bell state analyzer, we find a numerical trend that appears to approach a near -perfect measurement if we incorporate eight or more un-entangled ancilla photons into our device. Following this trend, we begin a promising inductive approach to building an ideal optical Bell measurement device. In the process, we determine that a...

Precision measurements are important across all fields of science. In particular, optical phase measurements can be used to measure distance, position, displacement, acceleration, and optical path length. Quantum entanglement enables higher precision than would otherwise be possible. We demonstrated an optical phase measurement with an entangled four-photon interference visibility greater than ...

Optical atomic clocks represent the state of the art in the frontier of modern measurement science. In this article a detailed review on the development of optical atomic clocks that are based on trapped single ions and many neutral atoms is provided. Important technical ingredients for optical clocks are discussed and measurement precision and systematic uncertainty associated with some of the...

Optical vector network analyzers (OVNAs) based on optical single-sideband (OSSB) modulation are of great interest thanks to the potentially high measurement resolution. However, the measurement accuracy of the OSSBbased OVNA is limited by the high-order sidebands in the OSSB signal. To study the influence of the high-order optical sidebands in OSSB signals on the measurement accuracy, an analyt...

A scheme is proposed for high-precision, absolute length measurement for an arbitrary optical distance of a few meters to beyond 10(6) m. The approach utilizes a phase-stabilized femtosecond laser to provide both incoherent, time-of-flight information and coherent, fringe-resolved interferometry. Such a combined measurement capability allows an optical wavelength resolution to be achieved for a...