We report the observation of high-intensity sub-Poissonian light using the correlated ‘‘twin’’ beams generated by an optical parametric oscillator. The intensity fluctuations in one of these beams are reduced by a feedforward correction mechanism that monitors the intensity of the second beam. The observed reduction in noise power is up to 24% below the shot-noise limit.

• Received 23 February 1990

DOI:https://doi.org/10.1103/PhysRevLett.64.2897