13-12-2010, 11:17 PM
FIBER OPTIC SENSORS
Presented by
Sherry Joseph George
S7 A R.No.42
College Of Engineering, Chengannur
Presented by
Sherry Joseph George
S7 A R.No.42
College Of Engineering, Chengannur
Contents
What is OFS
Basics of Optical fiber
Principle
Types of OFS
Applications
Advantages
Conclusion
FIBER OPTIC SENSORS?
Optical fiber sensor: A sensor that measures a physical quantity based on its modulation on the intensity, spectrum, phase, or polarization of light traveling through an optical fiber.
To measure physical parameters such as strain, temperature, pressure, velocity, and acceleration
Optical fibers: strands of glass that transmit light over long distances (wire in electrical systems)
Light: transmitted by continuous internal reflections in optical fibers (electron in electrical systems)
OPTICAL FIBRE
Total Internal Reflection
PRINCIPLE
TYPE OF FIBER OPTIC SENSORS
Extrinsic or Hybrid Fiber Optic Sensors
Intrinsic or All-Fiber Optic Sensors
Typical Optical Fiber Sensing Mechanism
Optical Transmitter
Definition: a device that converts electrical signal into optical signal
Lasers
Fabry-Perot Lasers (FP)
Distributed Feedback Lasers (DFB)
Vertical Cavity Surface Emitting Lasers (VCSEL)
Light Emitting Diodes (LED)
Surface-Emitting LED (SLED)
Edge-emitting LED (EELED)
Optical Receiver
Definition: convert optical signal into electrical signal
Types:
p-i-n photodetector: photon-electron converter
Avalance photodetector (APD): more sensitive for high speed systems
Intensity-based Fiber Optic Sensors
Spectrally-based Fiber Optic Sensors
Depend on the principle that a light beam can be modulated in wavelength by an environmental effect.
Interferometeric Fiber Optic Sensors
What Does F.O.S. Look Like?
Strain Gage
Embeddable Strain Gage
Pressure Transducer
Displacement Transducer
Temperature Transducer
ADVANTAGES
GENERAL USES
Measurement of physical properties such as strain, displacement, temperature, pressure, velocity, and acceleration in structures of any shape or size
Monitoring the physical health of structures in real time
Damage detection
Used in multifunctional structures, in which a combination of smart materials, actuators and sensors work together to produce specific action
Conclusion
Optical fiber sensors are superior to electric sensors in terms of sensitivity, immunity to EM radiation..
They can work at very high temperatures.
Constantly evolving technology.
It has got numerous applications.
References
Fiber optical intensity sensors : SHI-KAY YAO , senior member , IEEE
www.bluerrimages/Overview_of_FOS2.pdf
Optical Fiber Communications : John M.Senior
Fibre Optic Sensors and their applications
Fidanboylu, K.a, , and Efendioglu, H. S.b
a, Fatih University, Istanbul
b Fatih University, Istanbul.
www.bluerrimages/Overview_of_FOS2.pdf