Applications of single photons in quantum metrology, biology and the foundations of quantum physics

Abstract

The notion of photon shot-noise limit (also called Poisson noise) is very important for quantum metrology when dealing with single photon measurement.

Purcell‐Enhanced Single‐Photon Emission in the Telecom C‐Band

“…The Purcell enhancement is strongly dependent on the exact position of the QD with respect to the optical resonator mode. Thus, it can not be concluded whether any of the (2) (0) = 0.24 ± 0.1 is in agreement with the expected value estimated from the signal-to-background ratio in the μPL spectra.…”

“…As high‐performant sources of single photons, epitaxial quantum dots (QDs) can be considered as a semiconductor launchpad for quantum photonic technologies, [ 1 ] with applications in quantum metrology, biology, and the foundations of quantum physics, [ 2 ] as well as in quantum communications and computing. [ 3 ] Of particular interest are quantum dot single‐photon sources that emit light at wavelengths in the telecom C‐band between 1530 – 1565 nm, [ 4 ] which would allow for seamless integration into fiber telecommunication networks at lowest losses.…”

Polarization-Selective Enhancement of Telecom Wavelength Quantum Dot Transitions in an Elliptical Bullseye Resonator

“…S ingle-photon sources are an important building block for the advancement of emerging quantum technologies, such as quantum key distribution, 1−3 quantum metrology 4 and quantum computing. 5,6 For most applications, an optimal source should efficiently deliver indistinguishable single photons in a well-defined spatial and polarization mode.…”

“…Single-photon sources are an important building block for the advancement of emerging quantum technologies, such as quantum key distribution, − quantum metrology and quantum computing. , For most applications, an optimal source should efficiently deliver indistinguishable single photons in a well-defined spatial and polarization mode . Among the several platforms investigated over the last decades, semiconductor quantum dots (QDs) coupled to Purcell microcavities have shown excellent quantum-optical properties (high purity and indistinguishability) and state-of-the-art performance in terms of brightness and repetition rate. − Moreover, their ability to emit directly in the telecom O-band (1260–1360 nm) , or C-band (1530–1565 nm) , is crucial for the development of long-distance quantum communication networks , thanks to the low-loss windows of standard silica fibers at those wavelengths.…”

Polarized and Unpolarized Emission from a Single Emitter in a Bullseye Resonator

“…As of today, quantum dots (QDs) in semiconductors provide the best functionality to fulfill this role. [ 1–3 ] They were demonstrated as a leading platform in producing not only single photons, [ 4–7 ] but also pairs and strings of entangled photons. [ 8–14 ] A way to optimize these capabilities is to use optical micro‐cavities to support the QD emission.…”