The realm of nanooptics is usually characterized by the interaction of light with structures having relevant feature sizes
much smaller than the wavelength. To model such problems, a large variety of methods exists. However, most of them
either require a periodic arrangement of a unit cell or can handle only single entities. But there exists a great variety of
functional devices which may have either a spatial extent much larger than the wavelength and which comprise structural
details with sizes in the order of a fraction of the wavelength or they may consist of an amorphous arrangement of
strongly scattering entities. Such structures require large scale simulations where the fine details are retained. In this
contribution we outline our latest research on such devices and detail the computational peculiarities we have to
overcome. Presenting several examples, we show how simulations support the physical understanding of these devices.
Examples are randomly textured surfaces used for solar cells, where guided modes excited in the light absorbing layers
strongly affect the solar cell efficiency, amorphous metamaterials and stochastically arranged nanoantennas. The usage
of computational experiments will be motivated by the unprecedented insight into the functionality of such components.
We present a newly developed microscope for sum frequency generation (SFG) imaging of opaque and reflecting interfaces. The sample is viewed at an angle of 60° with respect to the surface normal in order to increase the collected SFG intensity. Our setup is designed to keep the whole field of view (FOV) in focus and to compensate for the distortion usually related to oblique imaging by means of a blazed grating. The separation of the SFG intensity and the reflected visible beam is accomplished by a suitable combination of spectral filters. The sum frequency microscope (SFM) is capable of in-situ chemically selective imaging by tuning the IR-beam to vibrational transitions of the respective molecules. The SFM is applied to imaging of structured self-assembled monolayers (SAM) of thiol molecules on a gold surface.
Conference Committee Involvement (3)
Nanofabrication: Technologies, Devices, and Applications II
23 October 2005 | Boston, MA, United States
Nanofabrication: Technologies, Devices, and Applications
25 October 2004 | Philadelphia, Pennsylvania, United States
19 May 2003 | Maspalomas, Gran Canaria, Canary Islands, Spain