The Optics Research Group currently has two positions for PhD students in the area of THz near-field microscopy.

Short description of the research

Under normal circumstances, light cannot be focused down to spotsizes with diameters smaller than approximately half-a-wavelength. For radiation with a frequency of 1 THz, which corresponds to a wavelength of 300 micrometers, this implies that it is impossible to study objects smaller than about 150 micrometer. This so-called diffraction limit thus poses a problem for the development of a THz microscope.
The research pproposed here is about methods to overcome the diffraction limit with the aim to develop a THz microscope which has a spatial resolution of about 100 nm in the 1-50 THz frequency range. This frequency range is attractive as many organic molecules have resonances in this frequencty range and such a microscope will have numerous biological applications.
Normally, the diffraction limit implies that when you illuminate an object with dimensions much smaller than the wavelength with THz light, the object has a negligible effect on the field very far away from the object, in the so-called far-field. It is only in the direct neighbourhood of the object that the THz field is significantly distorted.
We plan to investigate a number of new methods with which these near-field effects can be studied. These methods include the use of sharp metal tips, holes and other structures to concentrate light into a tiny volume and they require fundamental studies into the nature of the near-field, the effects of plasmons, and evanescent waves. The research requires that you work with state-of-the-art femtosecond lasers and optics and that you can collaborate well with others.

Requirements

- PhD candidates should have a Masters degree in Physics or Electrical Engineering. Knowledge of optics and lasers is recommended.

General information:

The Optics Research Group within the faculty of Applied Sciences is active in the field of wave propagation, diffraction and image formation. Apart from optical aperture synthesis for astronomical and space applications, current research topics are imaging with Terahertz radiation, subwavelength phenomena and lithography.

Application:

Application, curriculum vitae and possible list of publications to be sent to:
dr. P.C.M. Planken, E-mail: p.c.m.planken at tudelft.nl
More detailed information can be obtained from the same person (phone +31 15 2786965 and +31 15 2781444 )