Large-area fabrication of plasmonic nanostructures by interferometric lithography

Abstract

Plasmon resonances have attracted a great deal of research interest in recent years for their potential applications, including biosensing, subwavelength optics, negative refractive index metamaterials, as well as their ability to generate enhanced electromagnetic fields. Localised surface plasmon resonance (LSPR) in metallic nanostructures is able to provide large electromagnetic field enhancements, and nanometre-scale localisation of electric fields. Their resonance wavelengths and properties can be tuned by varying the nanostructure geometry and are very sensitive to the environmental refractive index. The coupling of LSPR can lead to new hybrid states that cannot be supported by individual metallic nanostructures, overcome certain limitations of single localised surface plasmon resonances, and open up possibilities for new applications as well as active control of plasmon resonances. The use of interferometric lithography (IL) to develop a variety of nanostructures has been and continues to be essential for mask production and biosensor application, and relies on its high resolution, flexibility, and compatibility with other conventional fabrication processes.