Squeezing in a refractive index-enhanced system

We consider a system of two-photon Raman transitions capable of refraction index enhancement while maintaining low absorption. In this system, the interference of the gain and absorption resonances of the probe beam results in interesting photon statistics properties including significant squeezing of the quantum states, of both photon-number and quadrature types, without the use of an explicitly nonlinear material. We investigate the conditions under which this happens.