At the center of world web connectivity, optical communications form an indispensable foundation. Key to this foundation are optical isolators, created by combining multiple components. The result’s a fancy structure that transmits light in just one direction, to stop damage to lasers and minimize noise by avoiding the reversal of sunshine. Nonetheless, some magnetic materials have an optical diode effect — an unconventional nonreciprocal absorption of sunshine manifested by the fabric itself. This effect results in a change in transmittance depending on the direction by which the sunshine travels. If this phenomenon might be enhanced, it is predicted that optical isolators might be made more compact and efficient.
A team of researchers led by Associate Professor Kenta Kimura of the Graduate School of Engineering at Osaka Metropolitan University investigated the phenomenon of nonreciprocal optical absorption within the magnetoelectric antiferromagnet LiNiPO4 at shortwave infrared wavelengths. Their results showed that the absorption coefficient differs by an element of two or more when the direction of sunshine propagation is reversed. This huge nonreciprocal absorption is attributed to the magnetic properties of the divalent nickel (Ni2+) ions. Moreover, the researchers have shown that it is feasible to change the optical diode effect with an applied magnetic field in a non-volatile manner.
“The optical diode effect is an interesting subject of study since it is such an unconventional phenomenon that is way faraway from common sense and has the potential to comprehend unexpected applications. Nonetheless, there are still many problems at present, equivalent to the low operating temperatures,” explained Professor Kenta Kimura. “Nevertheless, this research has demonstrated the usefulness of compounds containing nickel, which has greatly expanded the scope of fabric selection. Based on this data, we’ll proceed the event of materials exhibiting a better performance optical diode effect.”
Their findings were published in Physical Review Letters.
