  Surface lattice resonance (SLR) is the collective excitation of nanoparticle
resonances that exhibits both high quality factor and strong field enhancement.
While the quality factor of SLR stems from its unusual decay dynamics due to
the hybridization between localized surface plasmons (LSPs) and propagating
Rayleigh anomalies (RAs), the field enhancement is primarily attributed to the
extremely small effective mode volume. However, other than the mode volume, how
the light from the incidence is transferred to SLR so that the absorbed power
is the strongest is also of importance. We have studied the SLRs arising from
2D Au nanoparticle arrays by angle- and polarization-resolved reflectivity
spectroscopy, temporal coupled mode theory and finite-difference time-domain
simulation. The scattering matrix for the SLRs is analytically formulated,
revealing the importance of the interplay between the spectral detuning and the
interaction strength between the LSP and RA in governing the decay rates of
SLRs. On the other hand, we have identified the conditions for achieving the
strongest absorption of light in SLRs under one and two beam excitations. We
demonstrate the partial complete absorption of light in the arrays under single
elliptically polarized excitation for maximizing the field strength.
