1. AE2M32OSS - Optical Systems and Networks
Interferometric sensors
Mikhail Platonov

2. Mechanical measurements
Electrical and magnetic
measurements
Chemical and biological
sensing
Deformation Monitoring
of a concrete bridge deck
Pressure and strain sensors

3. Low coherence
interferometer based fiber
optic Microphone

4. Earthquake monitoring
of Structures
FOS can evaluate remaining
structures performance
Monitor structural
performance during an event
Detect inelastic response of
structural components
Can be monitored remotely
through internet

5. Traffic Monitoring
Speed monitoring
Weight sensing
Traffic light sensing

6. Naval Applications
ship structure monitoring
Other application areas:
- shape monitoring of towed
sonar arrays
- submersible testing
- lock gate monitoring
Technology allows any number of sensors to be
fitted anywhere in the ship for uninterrupted
recordings of actual degree of stress.

7. Submersible Testing
Measure strain on a deep
diving submersible to
depths of
1500 ft

8. Aerospace Applications
Mainly dealing with aircraft
structure and monitoring of:
- Wing shape design analysis
- acoustic crack emission
- hydrogen sensing
Monitoring: loads, rotor/fuselage
interaction, inboard rotor dynamics, hub
aerodynamics, airfoil pressure, wake/tail
interactions, fuel tank pressure, structural
integrity.

9. Dinner with a scientist

10. Why fiber optic sensors are so popular?
• Harsh environment capability: intensive EMI, high temperature, chemical
corrosion, high pressure, high voltage
• Light weight and small size
• Excellent performance: high sensitivity and large bandwidth
• Long range operation
• Multiplexed or distributed measurements

11. History
Armand Edouard Albert A. Karl
Hippolyte Stephan Michelson Schwarzschild
Fizeau

12. 50ft Interferometer (1931-
1938)

13. Fiber Optic Sensor Classifications
Sensing region: Intrinsic vs. Extrinsic
- Intrinsic fiber optic sensor has a sensing region within the fiber and
light never goes out of the fiber.
- In extrinsic sensors, light has to leave the fiber and reach the
sensing region outside and then comes back to the fiber.
Optical modulation mechanism

14. Intensity Modulated Fiber Optic Sensors
Basic structures
Reflection type Transmission type Differential intensity
sensors
Intensity based force sensor

15. Phase Modulated Fiber Optic Sensors
Two beam interferomenters
Michelson interferometer
Mach-Zehnder interferometer
Multi-beam interferometer
Fabry-Perot interferometer
Ring interferometer
Properties: high sensitivity compared to intensity based sensors

16. Wavelength Modulated Fiber Optic Sensors
Fiber Bragg Grating
Developed in 1978 by Canadian researchers Hill
Λ= pitch of the grating (period length)
A periodic change of the refractive index in the core
region of an optical
Bragg grating sensors for strain and temperature measurements

17. Wavelength Modulated Fiber Optic Sensors
Application areas Civil Applications
Civil infrastructure Monitoring bridge structures
Aircraft/space Traffic flow/weight monitoring
Oil/gas
Cure of concrete
Pipeline monitoring
Dam monitoring
Electric power and transport
Earthquake monitoring
Damage assessment systems
Geotechnical Application
Corrosion of structures, wind sensing
Health monitoring

18. Future Trends
New waveguides
New sensing mechanisms and sensor configuration
New fabrication technologies
High density fiber optic sensor networks