We show that nonlinear optical structures involving a balanced gain-loss profile can act as
unidirectional optical valves. This is made possible by exploiting the interplay between the …

This tutorial provides an intuitive and concrete description of the phenomena of
electromagnetic nonreciprocity that will be useful for readers with engineering or physics …

Isolators are devices that transmit waves only in one direction, and are widely used to
protect sensitive equipment from reflections and interference. These devices inherently …

Nonlinear isolators have attracted significant attention for their ability to break reciprocity and
provide isolation without the need of an external bias. A popular approach for the design of …

Here, inspired by the operation of conventional semiconductor transistors, we introduce a
novel class of bulk materials with nonreciprocal and non-Hermitian electromagnetic …

Reciprocity is fundamental to light transport and is a concept that holds also in rather
complex systems. Yet, reciprocity can be switched off even in linear, isotropic, and passive …

On-chip optical isolation plays a key role in optical communications and computing based
on silicon integrated photonic structures and has attracted great attentions for long years …

The fluorescence of Mn 2+ doped in the shell of CdS/ZnS core/shell nanocrystals at radially
controlled position is used as a local probe of pressure in the nanocrystal shell. The redshift …

Nonlinearity-induced asymmetric transport (AT) can be utilized for on-chip implementation of
nonreciprocal devices that do not require odd-vector biasing. This scheme, however, is …

Breaking reciprocity is fundamentally important for the protection of sources from incoming
signals and to route signals traveling in opposite directions asymmetrically. Nonreciprocal …