Extract Quantum Noise Squeezing from Intensity-Intensity Correlation in Optical Parametric Oscillators
Qing Xu1*
1Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
2Department of Physics, National Tsing Hua University, Hsinchu, Taiwan
3Physics Division, National Center for Theoretical Science, Hsinchu, Taiwan
* presenting author:Qing Xu, email:634223098@qq.com
Even though Heisenberg's uncertainty principle sets a limit on the detection of minimum noise, i.e., shot-noise level, quantum noise squeezing is also possible when the correlated photons are generated in optical parametric oscillators. Instead of homodyne detection scheme, in which two delicately balanced detectors make it not easily accessible, here we propose an alternative method to extract quantum noise squeezing from intensity-intensity correlation function, g(2), by superimposing the pump field and output field together in optical parametric oscillators. With the same superimposed fields, totally different photon statistics, from photon-bunching to anti-bunching can be obtained by adjusting the relative phase or amplitude of pump field.
The field–field correlation in cavity output extracted from this intensity-intensity correlation reveals the presence of quadrature phase squeezed state with a degree of squeezing by a factor of one half on the oscillation threshold.

Keywords: quantum noise squeezing, intensity-intensity correlation, bunching, antibunching