  We study the optical properties of Weyl semimetal (WSM) in a model which
features, in addition to the usual term describing isolated Dirac cones
proportional to the Fermi velocity $v_{F}$, a gap term $m$ and a Zeeman
spin-splitting term $b$ with broken time reversal symmetry. Transport is
treated within Kubo formalism and particular attention is payed to the
modifications that result from a finite $m$ and $b$. We consider how these
modifications change when a finite residual scattering rate $\Gamma$ is
included. For $\Gamma<m$ the A.C. conductivity as a function of photon energy
$\Omega$ continues to display the two quasilinear energy regions of the clean
limit for $\Omega$ below the onset of the second electronic band which is
gapped at ($ m+b $). For $\Gamma$ of the order $m$ little trace of two distinct
linear energy scales remain and the optical response has evolved towards that
for $m=b=0$. Although some quantitative differences remain there are no
qualitative differences. The magnitude of the D.C. conductivity
$\sigma^{DC}(T=0)$ at zero temperature ($T=0$) and chemical potential ($\mu=0$)
is altered. While it remains proportional to $\Gamma$ it becomes inversely
dependent on an effective Fermi velocity out of the Weyl nodes equal to
$v_{F}^\ast=v_{F}\sqrt{b^2-m^2}/b$ which decreases strongly as the phase
boundary between Weyl semimetal and gapped Dirac phase (GDSM) is approached at
$b=m$. The leading term in the approach to $\sigma^{DC}(T=0)$ for finite
$T/\Gamma$, $\mu/\Gamma$ and $\Omega/\Gamma$ is found to be quadratic. The
coefficient of these corrections tracks closely the $b/m$ dependence of the
$\mu=T=\Omega=0$ limit with differences largest near to the WSM-GDSM boundary.
