Atomic co-magnetometers, serving as high-precision magnetic area sensors, discover broad functions in autonomous navigation for unmanned methods and basic physics. Nevertheless, their standard optical detection modules counting on cumbersome parts endure from restricted miniaturization and integration. Metasurfaces supply a promising route towards optical path miniaturization. Nonetheless, most current metasurface designs deal with homogeneous polarization beam splitting, corresponding to separating linear polarization states, which may introduce extra optical noise and power loss. To beat this limitation, we suggest a linear-to-circular polarization differential detection scheme using a polarization-multiplexed metasurface. Via phase-encoded amorphous silicon meta-atoms fabricated on fused silica, this gadget integrates twin useful zones: a polarization-retaining deflector (PRD) and a polarization-converting deflector (PCD), enabling simultaneous beam splitting and unbiased manipulation of linearly polarized (LP) and circularly polarized (CP) gentle.On the operational wavelength of 795 nm, the meta-atoms exhibit over 80% transmittance. The PRD and PCD zones obtain deflection angles of +24.1° and -23.8°, respectively, with deviations under 1.5% from theoretical predictions. Experimental characterization demonstrates an optical rotation sensitivity of 5.9184×10⁻⁶ rad at 70 kHz, whereas the micron-scale thickness considerably enhances integration functionality. This work establishes a novel paradigm for chip-scale atomic co-magnetometers and advances the convergence of nanophotonics with atomic sensing applied sciences.
