ABSTRACT
Mid –infrared cavity Ring down spectroscopy using a cw diode laser
Jerome Remy, Marcel Hemerik, Gerrit Kroesen, Eindhoven University of Technology Applied physics dept, den Dolech 2 PO Box 513, 5600 MB Eindhoven, The Netherlands – EU
In the last years, dusty plasmas have undergone an explosion of scientific interest. A large part of this research effort is devoted to the understanding of the nucleation and growth of dust particles in silane plasmas. A powerful diagnostic tool based on the cavity ringdown spectroscopy technique is currently being improved for the mid-infrared spectral regions between 4 and 16 mm, using a helium cooled cw diode laser system and a confocal cavity inside the vacuum vessel. The first results obtained were very promising and preliminary detection sensitivity was 10-5. New considerations on the light source are developed, aiming at improving the beam quality, reliability and stability. The 0.1 mW low laser power output urges us to define the necessary light intensity we need inside the cavity. The main objective in the near future actually consists in optimizing the way we understand, send, control and detect the laser beam throughout his path. Very interesting characteristics of our diodes, as the geometric evolution of the active region as a function of temperature, have been noticed up to now and provide useful information. For further information: [email protected]
