  It is well established that nearly all high-quality (Q) Fano-like resonances
in terahertz (THz) metasurfaces broaden as asymmetry increases, resulting in a
decline of Q-factor and an increase in the resonance intensity. Therefore, in
order to determine the optimal design for applications in THz sensing, a Figure
of Merit (FoM) is required. Previous studies have identified the asymmetry
regimes at which the peak FoM occurs for various, specific unit cell
geometries. However to date, there is no systematic comparison of the resulting
FoMs for common and novel geometries. Here, a THz planar metafilm featuring
split ring resonators with four distributed capacitive gaps is investigated to
compare three unique methods of implementing asymmetry: (1) adjacent L-bracket
translation, (2) capacitive gap translation and (3) increasing gap width. The
results obtained find that by translating two gaps and increasing the bottom
gap width of the unit cell, the high-Q Fano-like resonances are $6 \times$
higher than the FoM for the fundamental dipole mode. This work further informs
the design process for THz metasurfaces and as such will help to define their
applications in photonics and sensing.
