  Control and detection of spin order in ferromagnets is the main principle
allowing storing and reading of magnetic information in nowadays technology.
The large class of antiferromagnets, on the other hand, is less utilized,
despite its very appealing features for spintronics applications. For instance,
the absence of net magnetization and stray fields eliminates crosstalk between
neighbouring devices and the absence of a primary macroscopic magnetization
makes spin manipulation in antiferromagnets inherently faster than in
ferromagnets. However, control of spins in antiferromagnets requires
exceedingly high magnetic fields, and antiferromagnetic order cannot be
detected with conventional magnetometry. Here we provide an overview and
illustrative examples of how electromagnetic radiation can be used for probing
and modification of the magnetic order in antiferromagnets. Spin pumping from
antiferromagnets, propagation of terahertz spin excitations, and tracing the
reversal of the antiferromagnetic and ferroelectric order parameter in
multiferroics are anticipated to be among the main topics defining the future
of this field.
