Materials Research Lecture

Flat optical devices based on lithographically patterned sub-wavelength dielectric nano-structures provide precise control of optical wavefronts. I present our work on high contrast transmitarrays and reflectarrays composed of silicon nano-posts located on low index substrates like silica glass and transparent polymers. Complete control of both phase and polarization is achieved at the level of single nano-post. Using this metasurface platform, we demonstrate lenses, waveplates, polarizers, arbitrary beam splitters and holograms.  Devices that provide multiple functionalities, like simultaneous polarization beam splitting and focusing are implemented. Conformal optical devices that decouple the geometrical shape and optical function are demonstrated using metasurfaces embedded in flexible substrates. Multiple flat optical elements are integrated in optical systems such as planar retro-reflectors and Fourier lens systems, with applications in ultra-compact imaging systems. Applications in microscopy and the prospects for tunable devices are discussed.

More about the speaker: Dr. Andrei Faraon is an Assistant Professor of Applied Physics at California Institute of Technology. After earning a B.S. degree in physics with honors in 2004 at California Institute of Technology, he received his M.S. in Electrical Engineering and PhD in Applied Physics both from Stanford University in 2009. At Stanford, Dr. Faraon was involved with seminal experiments on quantum optics using single indium arsenide quantum dots strongly coupled to photonic crystal cavities in gallium arsenide. After earning his PhD, Dr. Faraon spent three years as a postdoctoral fellow at Hewlett Packard Laboratories. At HP he was involved with pioneering experiments on diamond quantum photonic devices coupled to solid-state spins. He demonstrated the first nano-resonators coupled to single nitrogen vacancy centers in mono-crystalline diamond.

Faraon left HP in 2012 to become an Assistant Professor at Caltech. At Caltech, he set up a laboratory specialized in developing nano-photonic technologies for devices that operate close to the fundamental limit of light-matter interaction. He is focused both on fundamental challenges on how to control the interaction between single atoms and single photons using nano-technologies, and on using nano-photonics to build cutting edge devices for bio-imaging, bio-sensing and photo-voltaic energy harvesting. He is the recipient of the NSF CAREER award, the AFOSR young investigator award and the ONR young investigator award.

References:

1. Amir Arbabi, Yu Horie, Mahmood Bagheri, Andrei Faraon, Dielectric metasurfaces for complete control of phase and polarization with subwavelength spatial resolution and high transmission, Nature Nanotechnology 10, 937–943 (2015)

2. Mikael P. Backlund, Amir Arbabi, Petar N. Petrov, Ehsan Arbabi, Saumya Saurabh, Andrei Faraon, W. E. Moerner, Removing orientation-induced localization biases in single-molecule microscopy using a broadband metasurface mask , Nature Photonics, DOI:10.1038/nphoton.2016.93 (2016)

3. Amir Arbabi, Yu Horie, Alexander J. Ball, Mahmood Bagheri, Andrei Faraon, Subwavelength-thick Lenses with High Numerical Apertures and Large Efficiency Based on High Contrast Transmitarrays , Nature Communications, 6:7069, (2015)

4. Ehsan Arbabi, Amir Arbabi, Seyedeh Mahsa Kamali, Yu Horie, Andrei Faraon, Multiwavelength polarization-insensitive lenses based on dielectric metasurfaces with meta-molecules, Optica, Vol. 3, Issue 6, pp. 628-633 (2016)

5. Seyedeh Mahsa Kamali, Amir Arbabi, Ehsan Arbabi, Yu Horie, Andrei Faraon, Decoupling optical function and geometrical form using conformal flexible dielectric metasurfaces , Nature Communications, DOI:10.1038/ncomms11618 (2016)