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)

 

Time-resolved hyper-Rayleigh scattering: Measuring first hyperpolarizabilities beta of fluorescent molecules


Noordman OFJ, vanHulst NF
CHEMICAL PHYSICS LETTERS
vol 253 issue 1-2: p145-p150 APR 26 1996

Time-resolved hyper-Rayleigh scattering experiments using a femtosecond mode-locked Ti-sapphire laser are presented. The technique is capable of discriminating between hyper-Rayleigh scattered light and fluorescent emission induced by multiphoton absorption with a time resolution of 80 ps. Measurements o­n the non-fluorescent organic molecules crystal violet and calix- [4]arene demonstrate that the technique can measure first hyperpolarizabilities beta consistent with experiments using a Q-switched Nd:YAG laser. The first hyperpolarizability beta of a fluorescent molecule, which is often overestimated when using a nanosecond laser system, can be corrected for long-term fluorescence using the time-resolved technique as is demonstrated for the octupolar molecule 1,3,5-tris[(4- pyridyl)ethynyl]benzene.
Printable version