Publications de Jean-Philippe Besson

Molecular relaxation effects in hydrogen chloride photoacoustic detection

A photoacoustic (PA) sensor has been developed to monitor hydrogen chloride at sub-ppm level in the 1740-nm region. The system was designed to control the process in the novel low-water-peak optical fiber manufacturing process. Relaxation effects in hydrog ...

Springer Verlag2008

Molecular relaxation effects on hydrogen chloride photoacoustic detection

Luc Thévenaz, Jean-Philippe Besson

Connecticut College, New London, Connecticut USA2007

Near-infrared laser photoacoustic detection of methane: The impact of molecular relaxation

Luc Thévenaz, Jean-Philippe Besson

A photoacoustic sensor has been developed for trace-gas monitoring using a near-infrared semiconductor laser emitting in the 2ν3 band of methane at 1.65 μm. The apparatus was designed for on-line process control in the manufacturing of the novel low-water- ...

Springer Verlag2006

Multi-hydrogenated compounds monitoring in optical fibre manufacturing process by photoacoustic spectroscopy

Luc Thévenaz, Jean-Philippe Besson

Sub-ppm hydrogen chloride (HCl) and water vapour (H2O) monitoring using photoacoustic spectroscopy in optical fibre manufacturing is reported. The development and performance of a sensor based on an acoustic resonant configuration is described, and on-site ...

Springer Verlag2006

Sub-ppm multi-gas photoacoustic sensor

Luc Thévenaz, Jean-Philippe Besson

A photoacoustic multi-gas sensor using tuneable laser diodes in the near-infrared region is reported. An optimized resonant configuration based on an acoustic longitudinal mode is described. Automatic tracking of the acoustic resonance frequency using a pi ...

Elsevier2006

Ammonia trace measurements at ppb level based on near-IR photoacoustic spectroscopy

Luc Thévenaz, Jean-Philippe Besson

A photoacoustic sensor using a laser diode emitting near 1532 nm in combination with an erbium-doped fibre amplifier has been developed for ammonia trace gas analysis at atmospheric pressure. NH3 concentration measurements down to 6 ppb and a noise-equival ...

Springer Verlag2006

Photoacoustic spectroscopy for multi-gas sensing using near infrared lasers

Jean-Philippe Besson

Photoacoustic spectroscopy is a widely recognised technique to measure trace gases at parts-per-million (ppm) or parts-per-billion (ppb) level using semiconductor laser in the near infrared range. This technique is based on the generation of an acoustic wa ...

EPFL2006

Optical Sensor for the Detection of OH- Contamination during Optical Fibre Manufacturing

Luc Thévenaz, Jean-Philippe Besson

Sub-ppm (HCl) and (H2O) monitoring using photoacoustic spectroscopy is reported in optical fibre manufacturing for the production of low-water-peak fibres. Contamination sources of the carrier gas used for fibre preforms manufacturing were identified and d ...

Optical Society of America2006

Continuous and simultaneous multigas monitoring using a highly sensitive and selective photoacoustic sensor

Luc Thévenaz, Jean-Philippe Besson, Marcel Gyger

A multi-gas photoacoustic sensor is reported. Simultaneous measurement of ammonia, carbon dioxide and water vapor is demonstrated at ppm level using semiconductor lasers. In-situ measurements to control the housing conditions of laboratory animals are pres ...

IEEE2005

Methane monitoring by near infrared photoacoustic spectroscopy: The importance of relaxation phenomena

Luc Thévenaz, Jean-Philippe Besson

The importance of molecular relaxation in photoacoustic spectroscopy is discussed. The particular case of methane monitoring in dry oxygen using a 1.65-μm laser-based photoacoustic sensor is reported. The slow vibration-to-translation energy transfer occur ...

2005