Mirror-assisted backscattering interferometry to measure the first-order correlation function of the light emitted by quantum scatterers

We present a method to obtain the first-order temporal correlation function, ${g}^{(1)}(\ensuremath{\tau})$, of light scattered by an assembly pointlike quantum scatterers, or equivalently its spectral power distribution. This is based on mirror-assisted backscattering interferometric setup. The contrast angular fringes was already linked convolution ${g}^{(1)}(\ensuremath{\tau})$ for different Rabi frequencies taking into account incoming spatial intensity profile probe beam, but we show here that simply adding half wave plate interferometer in specific configuration, fringe becomes atoms, which are now all subjected same laser intensity. has direct application obtaining saturated spectrum systems. discuss some nontrivial aspects this setup and propose analogy with double Mach-Zehnder interferometer.