  Kinetic Inductance Detectors (KIDs) are superconducting energy-resolving
detectors, sensitive to single photons from the near-infrared to ultraviolet.
We study a hybrid KID design consisting of a beta phase tantalum ($\beta$-Ta)
inductor and a NbTiN interdigitated capacitor (IDC). The devices show an
average intrinsic quality factor $Q_i$ of 4.3$\times10^5$ $\pm$ 1.3
$\times10^5$. To increase the power captured by the light sensitive inductor,
we 3D-print an array of 150$\times$150 $\mu$m resin micro lenses on the
backside of the sapphire substrate. The shape deviation between design and
printed lenses is smaller than 1$\mu$m, and the alignment accuracy of this
process is $\delta_x = +5.8 \pm 0.5$ $\mu$m and $\delta_y = +8.3 \pm 3.3$
$\mu$m. We measure a resolving power for 1545-402 nm that is limited to 4.9 by
saturation in the KID's phase response. We can model the saturation in the
phase response with the evolution of the number of quasiparticles generated by
a photon event. An alternative coordinate system that has a linear response
raises the resolving power to 5.9 at 402 nm. We verify the measured resolving
power with a two-line measurement using a laser source and a monochromator. We
discuss several improvements that can be made to the devices on a route towards
KID arrays with high resolving powers.
