ORC Seminar Series

"Phase matching reexamined: wave mixing applications in ultrafast optics"


Professor Ian Walmsley
Oxford University

Date: Wednesday 14 November 2007
Time: 2pm
Venue: Building 46, Room 2005 (Lecture Theatre C)


Much of quantum optics has been enabled by the availability of nonlinear optical processes for the generation and manipulation of nonclassical states of light. A particularly useful resource has been the venerable process of frequency conversion in in crystalline materials. Despite its age, this well-studied process still has a few tricks up its sleeve that enable it to provide increased functionality in a number of applications involving ultrashort optical pulses. 

In this talk, we present an overview of recently developed ideas in ultrafast nonlinear optics, and describe a couple of applications in quantum optics where these ideas have had an impact. In particular, a closer look at three wave mixing of broadband electromagnetic fields in birefringent nonlinear crystals shows that not only phase matching, but also group velocity matching is important for understanding the process of up- and down-conversion with ultrashort laser pulses. In fact the higher-order dispersion of nonlinear crystalline materials provides an underused degree of freedom that allows tailoring the interaction so that it is suitable for a number of different applications.


Ian Walmsley is the Hooke Professor of Experimental Physics at Oxford, where he runs a research group studying quantum coherence on ultrafast timescales, and developing technology for ultrafast metrology. He studied at Imperial College, London and The Institute of Optics, University of Rochester, NY. After postdoctoral research at Cornell, he joined the faculty of the Institute, where he eventually served as Director in 2000 - 2001. He is currently Head of Atomic and Laser Physics at Oxford, and coordinator of the EU integrated project Qubit Applications.

Copyright University of Southampton 2006