  The 2 {\mu}m waveband is an area that could have significant technological
consequences, with applications ranging from spectroscopy, LIDAR and free-space
communications. The development of the thulium-doped fiber amplifier,
hollow-core photonic bandgap fiber and 2 {\mu}m GaSb-based diode lasers has
highlighted the ability of the waveband in alleviating the fiber capacity
crisis in the incumbent communication infrastructure. The above has initiated
vibrant development in the silicon photonic-space at 2 {\mu}m, where the area
is capable of enabling highly-integrated photonic circuits, and potentially at
low-cost and high-volumes. However, as of now, modulator linearity at 2 {\mu}m
has not been addressed. The metric, as characterized by spurious free dynamic
range is imperative for numerous applications such as RF photonic links for 5G
and digital analog transmission in coherent communications. The development of
linear optical modulators will be crucial in bringing these applications to the
2 {\mu}m. In view of that, this work is the first to address modulator
linearity at the 2 {\mu}m, where the ring-assisted Mach-Zehnder modulator is
developed, indicating spurious free dynamic range as high as 95 dB.Hz^2/3. It
is found that that modulator spurious free dynamic range has a strong
dependence on modulator bias voltage where it impacts the linearity of the
transfer function in which the input RF signal is applied upon. The
demonstrated modulator indicates favorable performance within silicon photonic
modulators developed at 2 {\mu}m with bandwidth exceeding 17.5 GHz and
modulation efficiency ranging from 0.70 to 1.25 V.cm.
