Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter at the nanoscale. We do this by exploring ways to shape light and its environment. It's what we call active and passive control. Our current focus is on the interaction of light with biomolecules and nanostructures. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.
We participate in the EU-COST actions MP1102: Coherent Raman microscopy (MicroCor) and CM1202: Supramolecular photocatalytic water splitting (PERSPECT-H2O)


Cerenkov-type second-harmonic generation in thin planar calix[4]arene waveguiding films

(full pdf)

Noordman OFJ, vanHulst NF, Bolger B
vol 12 issue 12: p2398-p2405 DEC 1995

A new type of organic molecule, calix[4]arene, is applied in a second-harmonic-generating waveguide device for the first time. Linear optical properties of the calix[4]arene waveguiding film have been measured with the prism-coupling method. The molecules in the film are oriented by a corona-poling technique. With a Maker-fringe experiment, the induced d(33) and d(31) at lambda = 1064 nm are determined at 8.6 and 2.0 pm/V, respectively. The calix[4]arene thin film has been applied to a Cerenkov-type device that generates second- harmonic light radiating into the glass substrate. The highest efficiency obtained is 0.23% for a fundamental wavelength of 820 nm by the use of fundamental power densities of 100 MW/cm(2) in the waveguide and a device length of 6 mm. A coupled-mode theory has been developed that can properly explain the experimentally observed second-harmonic-generating efficiency and the angle of radiation into the substrate. Two methods for the enhancement of device efficiency are proposed, both based on theoretical calculations with the coupled-mode theory. An enhancement of 2 orders of magnitude is feasible. (C) 1995 Optical Society of America
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