Magnetically Controllable CuB₂O₄Phase Retarder

Abstract

The modification of linear birefringence through electro- and piezo-optical effects has been applied in optical devices. In contrast, the control of linear birefringence by a magnetic field is not practically utilized since conventional magnetic linear birefringence is a second-order small effect. We report an approach to control linear birefringence with a first-order optical magneto-electric effect. The effect can provide a new type of phase retarder, which is magnetically controllable and propagation-direction dependent.

Nonreciprocal directional dichroism of a chiral magnet in the visible range

“…This unusual light-matter interaction is enabled by spin-orbit coupling, which gives magnetoelectric character to the on-site d-to-d excitations of Ni 2+ and analysis of the symmetry requirements led to the discovery of nonreciprocal effects in both the magnetochiral and transverse magnetochiral orientations. In the latter, field begins to control the overall magnetic moment even at the smallest values, which, combined with the use of unpolarized light, opens the door to a number of applications including optical isolators, rectifiers, and high-fidelity holograms [26][27][28] . Moreover, tests in which we compare switching H vs. k give a moderately consistent response in the magnetochiral case and nearly exact agreement in the transverse magnetochiral orientation.…”

“…In fact, the beauty of magnetochiral materials such as Ni 3 TeO 6 is that nonreciprocal directional dichroism can be observed with unpolarized light. The realization of polarization-independent nonreciprocal behavior in single-phase materials can be extremely useful for optical isolators and rectifiers in photonic integrated circuits and high-fidelity holograms [26][27][28] .…”

“…An electromagnon has natural magnetoelectric character and the energy scale of the light and that of the spins is similar. There are also examples of broadband nonreciprocal directional dichroism at higher energies -for instance, in GaFeO 3 32,33 and CuB 2 O 4 16,17,28,[33][34][35] . In many of the aforementioned cases, the authors reversed the direction of the external magnetic field rather than the light propagation direction.…”

Toroidal Order in Magnetic Metamaterials

“…More precisely, the OME can be understood as a combined Pockels and Voigt effect, both inducing linear birefringence. As a consequence, the origin of the effect does not have to be an intrinsic material property such as in a polar magnetic matter, but can be induced by applied electric and magnetic fields 489 . Both OME and MChE have in common that they manifest themselves in non-reciprocal directional-dependent material responses, associated for example with the sign of the light's propagation vector in optical experiments 69,180,458,461,462,490 .…”

Optical Effects in Artificial Magneto-Toroidal Crystals

“…More precisely, the OME can be understood as a combined Pockels and Voigt effect, both inducing linear birefringence. As a consequence, the origin of the effect does not have to be an intrinsic material property such as in a polar magnetic matter, but can be induced by applied electric and magnetic fields [5]. Both OME and MChE have in common that they manifest themselves in non-reciprocal directional-dependent material responses, associated for example with the sign of the light's propagation vector in optical experiments [6][7][8][9][10][11].…”