Dez River Araphid/Bi-raphid diatoms for nano-optic applications

Abstract

Micro and nano-silica structure technology is sumptuous and has empirical intricacies, so employing natural nanostructures can be inexpensive and more environmentally friendly. This green capacity can be the starting point of engineering and nanotechnology studies. Diatoms are good candidates for these structures, abundant in water and soil. They are types of algae with silicate frustules that may have periodic structures. Diatoms have a high potential to be used as sensors. They are very similar to photonic crystals.In this article, for the first time, some Araphid and Bi-raphid diatoms of the Dez River have been reported, and some of their optical characteristics have been investigated. The studied Dez-river Bi-raphid diatom shows no photonic band gap. Its periodic structure shows a maximum reflectance at λ=600nm, which seems to be an appropriate wavelength for the effective refractive index guiding mechanism through a siliceous defect. The studied Araphid diatoms show that the PBG waveguiding mechanism is achieved at the wavelength of about λ=690nm, too. This structure can be used as a narrow-band filter with a more than %95 efficiency for the mentioned wavelength. So the extraordinary structure of the Dez River Araphid and Bi-raphid diatoms can overtake the boundaries of the most advanced lithography techniques without spending time and money.