Projects

• Optical Power-Extinction Tomography:

Optical Power-Extinction Tomography (OPET) makes use of the power lost from two coherent beams, which simultaneously interrogate a scattering object, to generate a tomograph (three-dimensional image) of that object in a similar maner as Computed Axial Tomography (CAT) makes use of the attenuation of individual beams of X-rays through an absorbing object to generate a tomograph.

• Total Internal Reflection Tomography:

Total Internal Reflection Tomography (TIRT) is an imaging modality that makes use of evanescent waves to illuminate and probe a sample. The probe depth is controlled through the exponential decay of the evanescent wave. In principle, this form of illumination can also enable super-resolved imaging where features smaller that a wavelength can be resolved. To take practical advantage of this capability it is necessary to solve the inverse scattering problem which is the focus of this project.

• Near-field Optical Power-Extinction Tomography:

Near-field Optical Power-Extinction Tomography (NOPET) represents the intersection of TIRT and OPET where the probe beams of OPET are replaced with evanescent waves as in TIRT for sample illumination. With this technique it is possible to produce sub-wavelength resolved tomographs of scattering objects from the power lost from the probe fields.

• Near-field Scanning Optical Tomography:

Near-field Scanning Optical Tomography (NSOT) explores the extension of imaging modalities such as Photon Scanning Tunneling Microscopy (PSTM) and Near-field Scanning Optical Microscopy (NSOM) to samples that contains three-dimensional structure or when the probe tip is not scanned in grazing proximity to the sample. We solve the linearized inverse scattering problem to produce sub-wavelength resolved tomographs of the object under said conditions.

• Surface Plasmon-Polariton Modeling :

Surface Plasmon-Polaritons (SPPs) are quasi-two-dimensional waves supported at the interface of the vacuum (or a dielectric) and a metal with an index of refraction less than negative one. These waves are of great interest in the effort to produce integrated micro-optical elements at the intersection of micro electronics and micro optics. We are working with other groups on campus to better understand the behavior of these waves.

• Photon Scanning Tunneling Microscope:

A Photon Scanning Tunneling Microscope (PSTM) is a device where the object is illuminated by an evanescent wave generated at the face of a prism or slide and the field is detected via a fiber probe in the near-zone of the sample (as in NSOM). The data obtained with a PSTM is not amenable to direct interpretation but we show sufficient information exits in the raw data to numerically compute the two-dimensional structure of a thin sample, thus achieving a computational lens for the near-field

• Investigation of Carbon Nanotube Nano-Optics :

Carbon nanotubes and semiconductor nanowires are tiny objects (1000 times thinner than a human hair) that have recently drawn considerable attention in the scientific and engineering communities on account of their novel structural and electrical properties. Through the NER program and NSF funding we will theoretically investigate the optical and opto-electronic properties of these structures.