  Broadband electro-optic intensity modulators are essential to convert
electrical signals to the optical domain. The growing interest in THz wireless
applications demands modulators with frequency responses to the sub-THz range,
high power handling and very low nonlinear distortions, simultaneously.
However, a modulator with all those characteristics has not been demonstrated
to date. Here we experimentally demonstrate that plasmonic modulators do not
trade off any performance parameter, featuring - at the same time - a short
length of 10s of micrometers, record-high flat frequency response beyond 500
GHz, high power handling and high linearity, and we use them to create a
sub-THz radio-over-fiber analog optical link. These devices have the potential
to become a new tool in the general field of microwave photonics, making the
sub-THz range accessible to e.g. 5G wireless communications, antenna remoting,
IoT, sensing, and more.
