Double moiré localized plasmon structured illumination microscopy

Abstract

Structured illumination microscopy (SIM) is a well-established fluorescence imaging technique, which can increase spatial resolution by up to a factor of two. This article reports on a new way to extend the capabilities of structured illumination microscopy, by combining ideas from the fields of illumination engineering and nanophotonics. In this technique, plasmonic arrays of hexagonal symmetry are illuminated by two obliquely incident beams originating from a single laser. The resulting interference between the light grating and plasmonic grating creates a wide range of spatial frequencies above the microscope passband, while still preserving the spatial frequencies of regular SIM. To systematically investigate this technique and to contrast it with regular SIM and localized plasmon SIM, we implement a rigorous simulation procedure, which simulates the near-field illumination of the plasmonic grating and uses it in the subsequent forward imaging model. The inverse problem, of obtaining a super-resolution (SR) image from multiple low-resolution images, is solved using a numerical reconstruction algorithm while the obtained resolution is quantitatively assessed. The results point at the possibility of resolution enhancements beyond regular SIM, which rapidly vanishes with the height above the grating. In an initial experimental realization, the existence of the expected spatial frequencies is shown and the performance of compatible reconstruction approaches is compared. Finally, we discuss the obstacles of experimental implementations that would need to be overcome for artifact-free SR imaging.

Super-Resolution by Localized Plasmonic Structured Illumination Microscopy Using Self-Assembled Nanoparticle Substrates

“…Electron beam lithography (EBL), a technique renowned for its precision in crafting custom designs on lithographic resists, plays a crucial role in this process. In the context of LPSIM, EBL has been employed to create hexagonal arrays of silver nanodisks on glass substrates, subsequently coated with a thin layer of polymethyl methacrylate (PMMA) [18]. Another study demonstrated the fabrication of 60 nm silver nanodisks on a sapphire substrate, also coated with PMMA [19].…”

An overview of structured illumination microscopy: recent advances and perspectives

“…The spatial light modulator assisted [98][99][100][101][102] SIM system makes image acquisition speed faster than classical grating based system. Multiple Moiré illumination patterns [103][104][105] helps to achieve multi-fold resolution improvement over the widefield limit; this is similar to nonlinear SIM approach having higher harmonics without the requirement of special fluorophores. Periodic 2D pattern (e.g.…”

Directional Moiré Boosting Using Spatial Filtering

“…Caldero´n-Hermosillo et al [5] used the moiré technique on complex amplitude of the Spatial Light Modulator. The moiré technique has also been applied to the structural illumination microscopy [6,7]. Yu et al [8,9] worked on the visible moiré patterns and the influence of different grating frequencies on the resulting moiré patterns.…”