Sagnac interferometry and self-Kerr nonlinearity dependent photon drag

We present a theoretical investigation of the photon drag by incorporating self-Kerr nonlinearity (SKN) in a Sagnac interferometer featuring a four-level atomic system. By intro-ducing SKN in the system, we demonstrate significant improvements in the photon drag angles, ranging from & PLUSMN;10 micro-radians to & PLUSMN;1 centi-radians. Additionally, the presence of SKN leads to electromagnetically induced transparency (EIT), reduced group velocities, and a positive group index enhancement within the system. Conversely, in the absence of SKN, a negative group index is observed, accompanied by larger group velocities and minimal photon drag angles. The results obtained may have potential applications in various fields, such as slow-light detection, controlled image coding/design, efficient light modulators, and phase-matching in Brillouin scattering. Copyright ?c 2023 EPLA