Popular

Leonard Mandel

1927–2001 · quantum optics, physics
British-American physicist, one of the pioneers of quantum optics. He is best known as a co-discoverer of the Hong–Ou–Mandel effect, which demonstrates two-photon interference and the indistinguishability of quantum particles. His experiments and theoretical work laid the foundation for quantum information and quantum computing. He made significant contributions to statistical optics and the study of non-classical light.

Biography

Leonard Mandel was born on 9 May 1927 in Berlin, Germany. Due to his Jewish background, his family emigrated to England and then to the USA. He earned his doctorate at the University of London. He worked at Imperial College London and then at the University of Rochester, where he spent most of his career. Together with Chun Ki Hong and Zheyu Ou in 1987, he experimentally observed the effect of two-photon interference. He was awarded the Max Born Award and other honors. He died on 9 February 2001.

Key discoveries

💡 Mandel became interested in optics after attending a lecture by Dennis Gabor, the inventor of holography, which determined his future scientific path.
Quote: ""
Links in the knowledge graph 1
Related tags
quantum opticsquantum entanglementquantum informationquantum measurement
Related laws
Hong–Ou–Mandel effect
Related scientists
Charles TownesAlain AspectErwin SchrödingerDavid DeutschShuji NakamuraJohn Stewart BellNiels BohrAlbert A. Michelson

Related articles

Quantum Turnstile Network: 200 Users Fully Protected

Scientists launched the first large quantum network connecting 200 users over distances up to 200 km. The secret of protection lies in the behavior of two photons at a half-silvered mirror: if they are perfectly identical, they always go through together. It's like a turnstile that opens only for a
arXiv:2512.17318 · 2025-12-19

A Dimmer Reveals the Quantum Secrets of Light

A primitive light sensor can't tell what kind of light it sees, but physicists found a way: put a dimmer in front of it. By varying the dimming, the pattern of clicks reveals whether the light is quantum or classical.
arXiv:2601.13869 · 2026-01-20

Two Atoms Send Photons Marching in Triplets

Two artificial atoms linked by a waveguide made photons bunch into triplets. This is a step toward creating quantum simulators and studying exotic states of matter.
arXiv:2605.18525 · 2026-05-18

Light under Control: One-Way Photons Without Magnets

Light can be made to flow in one direction without magnets — just spin a ring resonator and use two amplifier atoms. A tiny frequency shift from rotation, like the change in a siren's pitch, after quantum wave interference creates a strong asymmetry: single photons emerge in one direction, bunched-u
arXiv:2605.27447 · 2026-05-24

Single Photons in High Harmonics

Scientists have theoretically proven that in extreme ultraviolet light from a laser, photons are born strictly one at a time. This discovery promises simple sources of single light particles for quantum communication and super-microscopy.
arXiv:2606.17620 · 2026-06-16