resonances. [5,6] A collective excitation (SLR) possesses a reduced linewidth as compared to the excitation of the LSPRs in nanoparticle ensembles. [1][2][3][4] Thus, SLRs can provide high quality-factor metasurfaces with substantial impact in nanophotonic and sensing applications. [1][2][3][4] Oblique incidence on planar metasurfaces constructed of an array of split-ring resonators showed that SLRs can also selectively respond to the handedness of circularly polarized light, causing sharp lattice-mode assisted extrinsic circular dichroism. [7,8] The spectral position of these SLRs can be tuned by the angle of incidence, leading to the emergence of extrinsic chiral surface lattice resonances. [9][10][11][12] Strong optical activity can also result from plasmonic 3D nanostructures without mirror symmetry. However, SLRs from arrays of 3D building-blocks with intrinsic chirality remain unexplored, but promise decreased losses and enhanced optical activity. [1,13] The fabrication of chiral 3D nanostructures is challenging for both, bottom-up and top-down methods. [14][15][16] Recently, the excitation of SLRs was seen in self-assembled, large area colloidal systems. [17,18] Such systems offer the possibility for fast manufacturing and covering large-areas on different substrate materials. [19] Colloid-based materials allow for embedding of nanoparticle arrays into flexible free-standing polymer films, [20] enabling the design of mechanically tunable [21] and stimuliresponsive hydrogel membranes. [22] Here, we use colloidal lithography [23][24][25] to fabricate arrays of 3D crescents with a selective response to the handedness of incident circularly polarized light, and we experimentally demonstrate handedness-dependent (chiral) SLRs at normal incidence. Colloidal lithography [23][24][25] is an experimentally simple and fast process to fabricate 3D chiral plasmonic nanostructures. [26][27][28] However, a necessary condition to observe SLRs in such nanostructure arrays is that their lattice constant must be in the range of the wavelength of the LSPRs of the individual nanostructures. [1][2][3][4] For objects with resonances in the near-infrared, such as, for example, split ring resonators, this requires large interparticle distances approaching the micrometer range. For conventional colloidal lithography processes, which depend on the controlled shrinkage of a polymer particle matrix, such distances are not easily achievable. [12,[28][29][30] Therefore, we use core-shell particles with rigid cores (silica) and soft, deformable polymer shells. [31,32] The particles selfassemble into hexagonally ordered monolayers at the air/water Collective excitation of periodic arrays of metallic nanoparticles by coupling localized surface plasmon resonances to grazing diffraction orders leads to surface lattice resonances with narrow line width. These resonances may find numerous applications in optical sensing and information processing. Here, a new degree of freedom of surface lattice resonances is experimentally investigated by dem...

Chiral plasmonic nanostructures hold promise for enhanced chiral sensing and circular dichroism spectroscopy of chiral molecules. It is therefore of interest to fabricate chiral plasmonic nanostructures with tailored chiroptical properties over large areas with reasonable effort. Here, a colloidal lithography approach is used to produce macroscopic arrays of sub‐micrometer 3D chiral plasmonic crescent structures over areas >1 cm2. The chirality originates from symmetry breaking by the introduction of a step within the crescent structure. This step is produced by an intermediate layer of silicon dioxide onto which the metal crescent structure is deposited. It is experimentally demonstrated that the chiroptical properties in such structures can be tailored by changing the position of the step within the crescent. These experiments are complemented by finite element simulations and the application of a multipole expansion to elucidate the physical origin of the circular dichroism of the crescent structures.

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