Analysis of Beam Steering of an Optical Nanoantenna Array
[Thesis]
Brar, Jarmanjeet Singh
Ahmed, Aftab
California State University, Long Beach
2020
43
M.S.
California State University, Long Beach
2020
Recent developments in nanofabrication technologies and plasmonics have generated a considerable interest for the field of nanoantenna, and several studies are being carried out to adapt the tested microwave and millimeter wave antenna concepts to the nanoantennas. The creation of phased arrays in the optical domain is an active area of research due to its applications in various fields such as sensing, optical microscopy, nanoscale imaging and spectroscopy, photovoltaics and many more. This thesis proposes the design of an optical phased nanoantenna array composed of metal and dielectric elements. The array is able to accomplish beam steering without any physical movement of the source or the array structure and without the involvement of electrical components such as phase shifters/drivers. As electrical components or hardware elements are not used, our design is relatively simpler, more practical and require minimum maintenance. Our design achieves beam steering by controlling progressive phase difference between consecutive dielectric elements. The phase difference between the elements is controlled by changing the refractive index of the electrically tunable dielectric elements by applying an external electric field. To analyze the design, an equivalent model was constructed using FDTD software and simulations were carried out for a range of refractive indices. Results from simulations showed that the design can attain a maximum beam steering angle of 58.6 degrees.