Active optical antenna

A compact source with sub-wavelength spatial resolution provides distinct advantages in a number of applications (microscopy, spectroscopy, optical data storage, lithography and laser processing). Limitations on throughput of near-field scanning optical microscopy (NSOM) fibers have led to work on very-small aperture lasers (VSAL), where a sub-wavelength aperture is placed on the facet of a diode laser. In recent years, much attention has been given to optical antennas, in particular due to their ability to couple light very efficiently to sub-wavelength dimensions. In this work, we implement optical antennas on the facet of a laser, thereby creating a new plasmonic device, termed an active optical antenna.

Ertugrul Cubukcu in collaboration with Ken Crozier (Harvard)

Mid-Infrared Optical Antenna

The purpose of this research work is to design and fabricate suitable antenna structures to concentrate incident mid-IR illumination to a sub-wavelength region with significant field enhancement, which may find application in infrared near field microscopy and chemical analysis. The antenna is fabricated on the facet of a quantum cascade laser. A scanning near field setup based on an atomic force microscope is constructed to characterize the field distribution around the antenna structure.

Nanfang Yu, Mikhail Belkin, and Laurent Diehl in collaboration with Ken Crozier (Harvard)

Engineering of Nanowire Surface Plasmon Resonances

Nanowires of noble metals have found applications in many fields, such as surface enhanced Raman scattering, and in optoelectronic circuits as waveguides to propagate light below the diffraction limit. Different applications, however, require nanowires with different surface plasmon resonance. In this project, we are exploring how the surface plasmon resonance of metallic nanowires can be tuned by appropriate design of their cross-sectional geometry.

Jiming Bao in collaboration with George M. Whitesides (Harvard)