Short Courses

SC293 Introduction to Fiber Sensors

Sunday, February 24, 1:00 p.m. - 4:00 p.m.
Michel Digonnet; Stanford Univ., USA

Level: Advanced Beginner (basic understanding of topic is necessary to follow course material)

Course Description
This course will start with a brief overview of the general features and applications of fiber optic sensors and their advantages relative to conventional sensors, as well as market opportunities and potential sizes. We will then describe the physical principles of the basic types of fiber sensors, namely intensity-modulated, interferometric and wavelength-modulated sensors. Specific architectures that will be covered include microbend sensors, Bragg and long-period fiber gratings, and Mach-Zehnder, Fabry-Perot and Sagnac interferometers. The bulk of the course will be a systematic review of the design, principle and performance of the fiber sensors developed to measure common specific parameters, such as rotation rate, temperature, strain, pressure, current, acceleration and chemicals. This will expose the attendees to the fundamental concepts of minimum detectable signal, dynamic range, interferometer biasing, polarization issues, light-source requirements, as well as sources of noise and means of reducing them. The last part of the course will cover demodulation schemes typically used to retrieve the information from fiber sensors, distributed sensors and multiplexing architectures (e.g., WDM and TDM) for addressing arrays containing a large number of sensors.

Benefits and Learning Objectives
This course should enable you to:

• Gain a detailed knowledge of the physical principles of a wide variety of fiber-optic sensors.
• Learn the various types of fiber-optic sensors available to measure a particular parameter (e.g., temperature or rotation rate).
• Understand the basic issues pertaining to the performance of fiber sensors, such as sensitivity, sources of noise, dynamic range, long-term stability, etc.
• Recognize some of the relative benefits of certain designs for a specific application.
• Understand how to multiplex multiple sensors in an array.
• Become aware of some of the opportunities for fiber-optic sensor markets.

Intended Audience
The course is intended for research and development engineers as well as industry and academic researchers who would like to gain a basic understanding of the physical principles and characteristics of a broad range of fiber-optic sensors. The course will also benefit communication specialists interested in using optical sensing technologies to monitor optical networks. Prior knowledge of the basic properties of optical fibers and common optical components is required for full benefit

Instructor Biography
Michel Digonnet received the degree of engineering from Ecole Supérieure de Physique et de Chimie de la Ville de Paris, the Diplome d'Etudes Approfondies in coherent optics from the University of Paris, Orsay, France (1978), and a master's degree (1980) and doctorate (1983) from the Applied Physics Department of Stanford University, California. His doctoral research centered on WDM fiber couplers and single-crystal fibers. From 1983 to 1986 he was a Visiting Scholar at Stanford, conducting research in miniature solid state sources and integrated optics for fiber sensors. From 1986 to 1990 he was involved in the development of dye and 2-µm solid-state lasers, fiber sensors, and fiber delivery systems for laser angioplasty at MCM Laboratories, Mountain View, California. Since then, he has been a senior research associate in Stanford University's Applied Physics Department. His current interests include photonic-bandgap fibers, fiber sensors and sensor arrays, high-power ceramic lasers, fiber lasers and amplifiers, fiber gratings, slow light, and optical micro-cavities. He has published 190 articles, issued nearly 60 patents, edited several books, and chaired numerous conferences on optical fiber devices, sensors and materials. He teaches a course entitled Lasers at Stanford, and other courses on fiber amplifiers and lasers, and fiber sensors at international conferences.