Alain Aspect performed experiments testing Bell inequalities at the Institut d’Optique.
Aspect and his collaborators carried out influential experiments in the early 1980s using pairs of entangled photons. They measured correlations between the photons’ polarizations while rapidly changing the measurement settings. The results violated Bell inequalities, agreeing with quantum-mechanical predictions and ruling out broad classes of local hidden-variable theories.
The work addressed a question raised by the Einstein–Podolsky–Rosen argument and formalized by John Bell in 1964. Bell’s theorem does not permit faster-than-light communication; instead, it shows that quantum correlations cannot be reproduced by theories satisfying both locality and certain assumptions about predetermined outcomes.
Aspect shared the 2022 Nobel Prize in Physics with John Clauser and Anton Zeilinger. Clauser performed earlier Bell-test experiments, while Zeilinger developed later experiments involving entanglement and quantum-information applications. The three laureates are therefore all linked to Bell tests, but Aspect is the scientist associated with the Institut d’Optique experiments in this question.