Presentation

The 3^rd "Journées" Terahertz will take place in Aussois at the CNRS centre Paul Langevin. The first edition was organized at the Paris Observatory on October 15, 1998 and the second edition took place in Dunkerque on March 14-15, 2002 where about fifty participants gathered. The aim of these "Journées" is to gather the french actors, researchers and industrialists who are involved in the THz domain or who are interested in its applications. The THz region covers the part of the electromagnetic spectrum, ranging from 100 GHz to 10 THz, that makes the link between microwave and optics. Since the end of the eighties with the development of THz time-domain spectroscopy, this domain knows an impressive expansion.

Nowadays, researches are directed towards compact sources, e.g. nanotransistors in the electronic domain or quantum cascade lasers in the optical domain, systems in the frequency domain using photomixing and the numerous emerging applications (non-exhaustive list):

- astronomy: molecular clouds spectroscopy - biology: genes sorting - chemistry: dynamics of physico-chemical reactions - defence: high security communications at short distance - environment : detection of pollution agent, air quality - imaging and tomography - medecine: detection of dermis cancers - microelectronics: measure of doping concentration - odontology: dental caries detection - security: detection of weapons and explosives - spectroscopy: characterisation of materials - telecommunications: local loop addressing - signal processing: smart filterring

This new window in the electromagnetic spectrum arouses a great craze in the scientific community and today this theme is sticked up in most of French conferences addressing the microwave and optics scientific communities. When the first edition of these "journées" was organized six years ago, the word "THz" did not offered the present echo. These "journŽes" THz still give the unique opportunity for the microwave and optics scientific communities to gather and for the actors who are working on the sources, detectors, systems and applications to exchange their views.

Recently confined to the laboratories, THz technologies start now to migrate to the industry due to the numerous emerging applications they arouse. This is the reason why a round-table dedicated to the potential transfer of THz technologies to the industry is planned to close these 3^rd "Journées" Terahertz