John P. Dakin, PhD, is Professor (Emeritus) at the Optoelectronics Research Centre, University of Southampton. He received the B.Sc. and Ph.D. degrees from Southampton University, U.K., and remained there as a Research Fellow until 1973 where he supervised research and development of optical fiber sensors and other optical measurement instruments. He then spent two years in Germany at AEG Telefunken, 12 years at Plessey, UK, and two years with York Limited/York Biodynamics before returning to Southampton University. He has authored over 150 technical and scientific papers, and over 120 patent applications. He was previously a Visiting Professor at Strathclyde University, UK. Dr. Dakin has won a number of awards, including "Inventor of the Year" for Plessey Electronic Systems Limited, the Electronics Divisional Board Premium of 1EE. Earlier, he won open scholarships to both Southampton and Manchester Universities. He has also been responsible for a number of key electro-optic developments. These include the sphere lens optical fiber connector, the first WDM optical shaft encoder, the Raman optical fiber distributed temperature sensor, the first realization of a fiber-optic passive hydrophone array sensor and the Sagnac location method described here, plus a number of novel optical gas sensing methods. Robert G. W. Brown, PhD, is chief executive officer of the American Institute of Physics. He received his PhD in engineering from the University of Surrey and his BS in physics from Royal Holloway College at the University of London. He was previously an applied physicist at Rockwell Collins, where he carried out research in photonic ultra-fast computing, optical detectors, and optical materials. Previously, he was an advisor to the UK government, and international and editorial director of the Institute of Physics. He is an elected member of the European Academy of the Sciences and Arts (Academia Eu