The Fiber-Optic Gyroscope: Achievement and Perspective

Special Seminar

Stanford University

Stanford, California (USA)

June 7, 2012

3:00 PM, Nano 143 (Center for Nanoscale Science and Engineering)

http://events.stanford.edu/byCategory/22/

The Fiber-Optic Gyroscope: Achievement and Perspective

General Public, Faculty/Staff, Students, Alumni/Friends

Sponsor:  Applied Physics Department, and Ginzton Laboratory

Contact:  ingrid@ee.stanford.edu

Hervé C. Lefèvre

Chief Scientific Officer

IXBlue SAS (France)

herve.lefevre@ixblue.com

  

Both optical gyroscopes, the ring-laser gyro (RLG) and the fiber-optic gyro (FOG), are based on the same Sagnac effect, which shows that light travelling along a closed ring path in opposite directions allows one to detect rotation with respect to inertial space. Over one turn, as in the original experiment, the effect is extremely weak, but it can be increased with recirculation in the resonant cavity of a ring laser or using the numerous loops of a fiber coil. The RLG was demonstrated only a few years after the invention of the laser in 1960, and it is based on helium-neon (He-Ne) technology. It became very successful in the 80s and has since overcome classical spinning-wheel mechanical gyroscopes because of its improved lifetime and reliability. It was clear progress but gas lasers still have several drawbacks, such as high-voltage discharge electrodes, which tend to wear out over the long term, or the need for perfect sealing of the gas enclosure. The advent of low-attenuation optical fiber and efficient semiconductor light source in the 70s opened the way for a fully solid-state device. Then, however, the FOG was seen as an approach limited to medium performance, but unable to compete with the RLG for top-grade applications. As we shall see, this is not the case anymore.

Biography

Dr. Hervé Lefèvre graduated from Ecole Normale Supérieure de Saint-Cloud (France) in Physics and was awarded a Doctorate in Optics-Photonics from the University of Paris-Orsay (France) in 1979. His doctorate research was performed at Thales (then Thomson-CSF) Central Research Laboratory, and his thesis subject was pioneering work on the fiber-optic gyroscope. From 1980 to 1982 he was a post-doctoral research associate at Stanford, continuing R&D on the fiber-optic gyroscope. In 1982 returned to Thales Central Research Lab in France and became head of the fiber-optic sensor team. In 1987 he joined Photonetics, then a start-up, and became director of R&D. In addition to fiber-optic sensors and gyroscopes, the company developed a very successful line of test instruments for optical fiber communications. As the company grew, he moved to the position of Chief Operating Officer in 1999. At the end of 2000, Photonetics was acquired by the Danish group Nettest, while its fiber-gyro activity was spun out to create iXSea. Hervé remained in Nettest and managed its Photonics Division. 
In 2004 he moved to iXCore, the parent company of iXSea, as Vice-President for R&D with a specific involvement in iXSea's activity, and became Chief Scientific Officer of iXBlue at its creation in 2010. Dr. Hervé Lefèvre is also President of the European Optical Society (EOS).