Nanoscale Characterisation of Optical Systems and Devices

JPK Instruments reports on the work from the Light Technology Institute at the Karlsruhe Institute of Technology (KIT) in Germany where the JPK NanoWizard® family of AFMs provide the backbone for topographic and optical research activities.

Dr Hans Eisler heads the DFG Heisenberg Nanoscale Science Group in Karlsruhe. It currently focuses on the development, engineering and application of quantum world based proof-of-principle devices such as single photon sources with directional emission properties at room temperature, novel energy harvesting devices comprised of resonant optical antennas, or optical antenna mediated near-field probes for microscopy and spectroscopy. The group utilises so-called top-down nanotechnology approaches such as e-beam lithography to create functional nanodevices. Since Hans Eisler is a chemist by professional training, the DFG Heisenberg Group also uses nanochemistry to meet the requirements for bottom-up nanotechnology in the field of colloidal quantum dot research. In order to study such complex and experimentally demanding devices there is a need to correlate, whenever possible, optical information with topography information. Thus, the optical workhorse is an (inverted) epi-fluore scence microscope combined with an atomic force microscope (AFM). The optical methods include widefield fluorescence, tip-enhanced Raman Spectroscopy (TERS), darkfield microscopy and confocal microscopy under onephoton and multi-photon excitation. The AFM triggers the topography experiments and more recently has helped to create plasmonic architectures such as resonant optical antennas via nanomanipulation schemes.

Speaking about his research goals, Eisler said: "We want to learn about the nanoscale science of matter interacting with light and vice versa to generate new ideas for future technologies based on quantum world language and principles. This includes the whole range of nanoscale fabrication and characterisation."

Continuing, Eisler has positive words of praise for the JPK range of products: "Our JPK package not only includes a very nicely engineered AFM workhorse, but also has the benefit of an open software interface and an easily accessible hardware interface to combine AFM technology with other methods such as time correlated single photon counting (TCSPC). Even more importantly for us than just the naked machinery is the outstanding application and service delivered to us in a very short time frame. As we are doing research in a very competitive field, we can thus completely focus on our science and an absolutely reliable workhorse.”