May 10, 2005

BNL Workshop on Intense Coherent THz Pulses

The first workshop on intense coherent THz pulses at Brookhaven National Laboratory (BNL) was held during the spring of 2005. Participants included scientists from regional universities and institutions as well as members of the BNL scientific community.

Participants in the Workshop on Intense Coherent THz Pulses

The workshop focused on the science enabled by linac sources of intense coherent terahertz (THz) radiation. The NSLS Source Development Lab (SDL) linac is one such source, producing 100-microjoule, single-cycle coherent pulses with spectral content reaching to a few THz. The full-day workshop began with a presentation by Xi-Jie Wang (NSLS) that described how the SDL linac produces ultra-short, high-charge electron bunches that generate coherent THz pulses or deep ultraviolet free-electron laser light. Larry Carr (NSLS) followed with a description of the SDL's THz pulses, including measurements of the pulse energy, spectral content, and electro-optic detection instrumentation. He emphasized applications where the THz pulses serve as an excitation source rather than simply a probe of a material's response. Tony Heinz (Columbia University) gave an overview of THz methods, current scientific efforts, and the frontiers opened by a source of high intensity THz pulses. Ivan Bozovic (BNL Materials Science) described ultra-fast THz studies of correlated electron systems and complex oxides - material systems of great interest at Brookhaven. Toni Taylor (Los Alamos National Laboratory) presented other THz studies of complex materials in a seminar the following day. The National Institute of Standards and Technology (NIST) uses THz methods to study complex biomolecules. Ted Heilweil (NIST) discussed that activity as well as applications of THz in homeland security and imaging. It has been noted that the magnetic field portion of a THz wave could be sufficient to change the magnetization state of some magnetic alloys, a topic Dario Arena (NSLS) summarized in his talk. The connection between THz and magnetization dynamics was also described in Toni Taylor's presentation.

Attendees were given a tour of the SDL facility and the location for future THz studies. This was followed by a discussion session that helped to define experimental directions and provide recommendations on the facility and instrumentation requirements.

RELATED LINKS: Workshop Website

ARTICLE BY: Larry Carr