Nonreciprocal Beam Splitters and Wavevector Discretization in Magneto-Optics

We present a description and experimental verification of nonreciprocal multiple circular reflection/refraction in magneto-optic materials. This rarely explored phenomenon can be applied for the creation of nonreciprocal beam splitters. The effect enables the separation of light into multiple beams of opposite helicity elliptically and linearly polarized beams, each traveling in different directions. The presentation will provide a mathematical description and experimental validation of this phenomenon in the visible and near-infrared, using bismuth-substituted iron garnets. Additionally, this work verifies wavevector discretization in reflection in bulk magneto-optics, revealing a multiplicity of modes present in elliptical and linear polarization pairs. This phenomenon is unrelated to confinement or resonance effects but arises from variations in refractive index with beam propagation direction. We present theoretical and numerical solutions, along with computational verification in bismuth-substituted iron garnets. These results hold promise for classical and quantum applications, for potential nonreciprocal and multi-functional photonic devices, including beam steerers, isolators, and routers.