Nanofabrication technology can be used to create structures whose physical properties vary at length scales significantly smaller than the wavelength of light. Such engineered structures can be used to manipulate the propagation of light at the nanoscale and confine optical fields to very small volumes. The resulting high fields lead to much stronger light-matter interactions than observed in bulk media. Optics and photonics in such nanoscale systems present a number of opportunities and challenges from both a scientific and technological perspective. For example, by exploiting enhanced light-matter interactions within chip-scale geometries created using scalable fabrication processes, one can envision a broad array of sensing, communications, and metrology tools that can be used in a variety of different environments and can eventually be mass-produced. On the other hand, the successful realization of such devices can require detailed numerical modeling to design structures with a desired physical behavior, novel, sophisticated, and robust fabrication methods to manufacture them, and innovative measurement solutions to determine the extent to which the model predictions are experimentally realized.
CNST's research efforts in nanoscale optics and photonics thus includes the development of core competencies in the areas of design/simulation, nanofabrication, and measurement. Computational tools such as the finite-difference time-domain and finite element method are used to quantitatively model the behavior of light within nanoscale geometries and the strength with which light interacts with media such as nonlinear optical materials and resonant mechanical structures. The world-class facilities in the CNST NanoFab are used to realize nanostructures in widely varying material systems, and to integrate nanoscale optics with electronics and mechanics to create highly functional platforms capable of addressing a range of sensing and signal transduction applications. A host of custom measurement solutions have been and continue to be developed, enabling flexible interrogation of materials and devices within different environments. These include in situ optical measurements within ion and electron microscopes, cryogenic near-field and far-field spectroscopy and time-correlated single-photon counting, photonic probe stations for guided wave coupling, and deposition and localization of fluorescent and plasmonic nanoparticle indicators.
Using these resources, CNST staff are conducting research in areas such as understanding radiation pressure optical forces in dielectric media and metamaterials, manipulating the spectro-temporal properties of quantum states of light, mapping the optical modes of nanophotonic devices using custom focused ion beam technology, and testing the nanoscale motion of complex mechanical systems through optical nanoscopy. They are developing technologies such as compact force and displacement sensors based on cavity optomechanical systems, nanomechanical transducers that connect microwave and optical signals, ultracompact and nano-electromechanically tunable plasmonic modulators, integrated quantum optical light sources and frequency conversion hardware, asymmetric light transmission devices using metamaterials, and compact time and frequency metrology tools based on nanophotonics. These efforts, described in more detail below, are being conducted in collaboration with a large number of research participants, both from the different divisions within NIST as well as from external institutions in industry and academia.
Selected Publications:
All-angle negative refraction and active flat lensing of ultraviolet light, T. Xu, A. Agrawal, M. Abashin, K. J. Chau, and H. J. Lezec, Nature 497, 470–474 (2013).
NIST Publication Database Journal Web Site Related Link: News Story
A microelectromechanically controlled cavity optomechanical sensing system, H. Miao, K. Srinivasan, and V. Aksyuk, New Journal of Physics, 14, 075015 (2012).
NIST Publication Database Journal Web Site Related Link: News Story
Quantum transduction of telecommunications-band single photons from a quantum dot by frequency upconversion, M. T. Rakher, L. Ma, O. Slattery, X. Tang, and K. Srinivasan, Nature Photonics 4, 786-791 (2010).
NIST Publication Database Journal Web Site Related Link: News Story