Enhanced rotary photon drag via phase and angular momentum dependent Raman gain in a Mach-Zehnder type Sagnac interferometer

The dependence of phase and orbital angular momentum (OAM) of the pump and control fields in a Raman gain-assisted four level atomic system using a Mach-Zehnder type Sagnac interferometer (MZSI) is proposed for the investigation of rotary photon drag. Gain doublets and normal/anomalous dispersion are noticed for appropriate values of strengths, phases and OAM of the pump and control fields. Relativistic group velocities of the two counter propagating beams are examined as a function of phase angle and fluctuations are observed for different values of the OAM. Significant improvements in the rotary photon drag angles from ±5 micro-radians to ± 1 centi-radians are achieved as a function of phase angle of the pump and control fields. The results obtained could have potential applications in rotation sensing technology, position control and optical communication technologies.