While studying Faraday rotation (linear magneto-optic rotation) I came across a fact that faraday rotation can be enhanced. Verdet constant which depends on the wavelength can be enhanced as change in refractive index with change in wavelength is maximum near resonant light. Now if the incident light frequency is resonant with the atomic transition frequency then light will get absorbed in the medium and we'll get very less light at the output for observation. It is my understanding that optical pumping is done to make medium transparent to the resonant light, as when majority of electrons will be trapped in dark state we'll get considerable light at the output to measure change in the plane of polarization. Is my understanding accurate or is there anything that i have missed? Does optical pumping enhance faraday rotation in some other way also?