Revealing Anti-Ferromagnetic Domains with Linear Non-Reciprocal Optical Effects

I show that domains in anti-ferromagnetic crystals that break inversion symmetry as well as time-reversal symmetry can be characterized using linear non-reciprocal optical effects detected with Sagnac-interferometry-based microscopy. In addition, a simultaneous detection of these effects from oppositely aligned domains yields a background-free measurement of non-reciprocal optical susceptibilities.