Design and Fabrication of Optical Metamaterials and Their Nano Manufacturing Methods
Metamaterials have opened a new field of optics in science and engineering. Negative refraction has been achieved by manipulating permittivity and permeability to be negative using the combination of SRRs (split ring resonators) and metal wires and the fishnet structure. However, the fishnet design suffers two significant disadvantages: anisotropy and scalability. The fishnet metamaterial needs a specific polarization direction because of the limitations of anisotropic design. In addition, the conventional projection photolithography approach to nanoscale manufacturing is facing possibly insurmountable challenges in economically producing the next generation of semi-conductor integrated circuits. Maskless nanolithography is a potentially agile and cost effective approach, but most of the current solutions have throughputs that are too low for viable manufacturing purposes. This dissertation presents novel isotropic and chiral metamaterials as well as a plasmonic lithography approach to mass metamaterial manufacturing.
This dissertation reports two new designs of metamaterial which have a negative index of refraction and overcome the disadvantage of conventional metamaterials. The design of a chiral metamaterial is proposed, fabricated, and measured to prove negative index of refraction. Furthermore, a tunable chiral metamaterial is proposed, which is able to switch left and right circular polarized light dynamically by an external control beam. Also shifted bars and rings create a negative refractive metamaterial which is isotropic and randomly distributed. In this thesis, two shifted rings structure are proved to have a negative index of refraction independent of the direction of polarized light or without polarization. Beside applications of negative refraction, other applications are studied. The split ring resonator is one of the basic structures of metamaterial and this structure can be used to measure mode volume and single molecule detection by far field method.
For the nano manufacturing method, using the plasmonic nanolithography (PNL) approach, 22-nm half-pitch direct pattern writing was successfully demonstrated using ultra-fast laser assisted nanoscale heat management and advanced plasmonic airbearing flying head designs. In addition, the details of micro and nano fabrication methods are introduced and they cover all of the structures proposed in this thesis.