Resonant Photonic Structures and Metasurfaces

The metamaterials and metasurfaces consist of periodical sub-wavelength metals and medium structures with unique physical properties derived from the design parameters, shape, and orientation of building blocks, that resonantly couple to the electric and magnetic fields of the incident electromagnetic waves, exhibiting extraordinary electromagnetic properties. Some of the examples of metamaterials include negative-refractive-index materials, chiral materials, electromechanical metamaterials, and photonic crystals, and they can be applied to some difficult areas of conventional optics, such as super-resolution imaging, electromagnetic cloaks, and all-optical devices. Three-dimensional (3D) functional metamaterial structures of different basis orientations, such as helical shapes and stacks of U structures, can mold a broad spectrum of electromagnetic waves for unique applications in infrared and optical frequencies. In our lab various metamaterial structures of different shapes and orientations are fabricated through direct laser and phase engineered interference lithography. Some examples are the periodic arrangement of 3D metallic helices with a certain pitch comparable to the wavelength of light shows Bragg resonances; c-shaped metamaterials with phase discontinuity show broadband anomalous deflection; a stack of u-shape metamaterials show magnetism at optical frequencies and L-shaped metamaterial structures show chirality that leads to negative refractive index for one of the circularly polarized lights.

Publications

Behera, Saraswati, and Joby Joseph. "Design and realization of functional metamaterial basis structures through optical phase manipulation based interference lithography." Journal of Optics 19.10 (2017): 105103.

Behera, Saraswati, and Joby Joseph. "Metamaterial structures of variable and gradient basis orientations embedded with periodic linear defects: phase engineered design, single step optical realization, and applications." Applied optics 58.1 (2019): 50-55.