Tuesday June 28, 2005
11:30 AM - 1 PM
ENG Z-50 Auditorium

Office Hours:
Friday July 1, 2005
3:30 PM - 4:30 PM
ENG B-18

"Nanofocusing of visible and infrared light for microscopy"
Dr. Fritz Keilmann
Max-Planck-Institut fur Biochemie

Light has traditionally been focused by lenses and concave mirrors, to minimal spot sizes of half a wavelength (Abbe limit of light microscopy). This lecture deals with concepts that have allowed or hold future promise of much finer light spots in the 100-1 nm range, and thus bear the potential of a light microscopy with nanometric resolution. These concepts exploit the interaction of light with material structures such as optical waveguides or optical antenna structures that concentrate the light near some nanometric feature, in most cases a sharp tip that can be scanned to generate an optical nanograph. An arresting insight is that the obtainable focus size is defined by the achievable sharpness of the tip, but not by the light wavelength. This allows to develop optical nanoscopy with long wavelength infrared radiation, a region that bears interesting spectral contrasts but has never played a role in classical microscopy.