Approaching quantum-limited amplification with large gain catalyzed by   hybrid nonlinear media in cavity optomechanics
  Amplifier is at the heart of almost all experiment carrying out the precise measurement of a weak signal. An idea amplifier should have large gain and minimum added noise simultaneously. Here, we consider the quantum measurement properties of a hybrid nonlinear cavity with the Kerr and OPA nonlinear media to amplify an input signal. We show that our hybrid-nonlinear-cavity amplifier has large gain in the single-value stable regime and achieves quantum limit unconditionally. 
Qiang Zheng, Kai Li, Yong Li
quant-ph