Photonics technologies: Generation and application of quantum-correlated twin beams

Abstract

The signal and idler beams from a non-degenerate, above threshold, optical parametric oscillator have a strong quantum correlation, which are called twin beams. This correlation arises from the simultaneous generation of the signal and idler photons in the form of twin pairs of photons through the parametric down conversion, and the generated twin beams have exactly the same photon statistics. As a result, the fluctuations on the difference between the intensities of the twin beams are reduced with respect to the shot-noise limit, that is, intensity-difference squeezing. There has been observed squeezing of 8 dB (84 percent) on the intensity difference between the twin beams generated by a semimonolithic optical parametric oscillator. In this paper, a comprehensive overview of the generation of twin beams using the optical parametric oscillator and the applications exploiting the quantum correlation of twin beams are presented.