NIST researchers are developing a technology to generate single photons on demand using tiny semiconductor structures called quantum dots. The goal is to create a reliable source that emits individual particles of light with near-perfect efficiency, overcoming current limitations where photons are produced randomly. Currently, the team captures over 40% of emitted photons using specialized cavities, with a target to reach 90% efficiency to support high-performance applications.
This research lays the groundwork for future standards in photonic quantum computing and quantum networks, which require consistent and identical photons to operate. A major long-term objective is to redefine the candela, the SI unit for light brightness, to reduce measurement uncertainty in metrology. While the technology is still in the research phase, NIST aims to eventually replace bulky calibration equipment with compact, chip-scale sources for more precise industry standards.
Source: https://www.nist.gov/noac/technology/quantum-optics-and-radiometry/single-photon-sources
Keywords: single-photon sources, quantum dots, molecular beam epitaxy