Nanfang Yu

He has found that nanostructured materials usually turn out to be superb solutions for the generation, control, and detection of infrared waves with long wavelengths. For example, quantum cascade lasers, the most popular coherent infrared light sources, are made of semiconductor superlattices, which comprise a stack of nanometer-thick semiconductors, the thinnest layer being only a few atoms thick.

Yu and his lab work to create a new class of flat optical components, the thicknesses of which are just one-thousandth of a human hair and yet are able to do all the jobs conventional, bulky optical components can do. These flat optical devices are made of a two-dimensional array of nano optical scatters, which can individually and abruptly change the amplitude, phase and/or polarization of the scattered light. Together, the array of scatterers can dynamically mold optical wavefronts into arbitrary shapes with ultra-high speed.

Yu believes flat optics are the key to creating modulators for infrared light, which will open up completely new application areas such as all-weather free-space optical communication and remote-sensing optical radar.

To build better infrared detectors and communication systems, Yu probes the clever strategies developed by infrared-sensing organisms over their long evolutionary history. He is conducting interdisciplinary research with biologists and ecologists, exploring ways in which certain insects are able to detect broadband thermal radiation with extremely high sensitivity and spatial accuracy, or detect infrared “fingerprint” emissions from chemicals with high specificity. These studies will have a broad impact on novel heat-sensing devices and chemical detection systems.

Yu received a BS in Electrical Engineering from Peking University in 2004 and a PhD in Engineering Sciences from the School of Engineering and Applied Sciences at Harvard University in 2009. Yu joined Columbia University in 2013 after completing his doctoral and postdoctoral work at Harvard University. At Harvard, Yu worked extensively on plasmonics, metamaterials, and mid-infrared and terahertz semiconductor lasers. He is a contributing member of a number of professional societies including the Optical Society of America, the IEEE Photonics Society, the American Physical Society, and the Materials Research Society.
 

Research Areas

• Atomic, Molecular, and Optical (AMO) Physics
• Condensed Matter Physics
• Solid-State Physics
• Biophysics
• Photonics and Optics
• Quantum Information Science
• Quantum Materials
• Soft Matter
• Advanced Materials