Observation of quantum-correlated twin beams in cascaded nonlinear interactions
Salvatore Castrignano, Iolanda Ricciardi, P. Maddaloni, Paolo De Natale, Stefan W. Wabnitz, M. De Rosa · Optics Letters · 2024
We report on the generation of twin beams through a cascaded process of optical parametric oscillation in a doubly resonant second-harmonic generation system. These bright beams exhibit strong quantum correlations, enabling the observation of up to 5 dB of noise reduction in their intensity difference below the standard quantum limit.