1. Photonic technologies for aerospace applications
Mauro Varasi (Finmeccanica)
Roma - August 20th, 2008

2. Outlook
Photonics: where optics meet electronics
Why photonics
Structural Monitoring: FBG
Gyro
Radar
Data Links
New technological frontiers
Conclusions

3. Photonics: where optic meets electronic ….. ….. in airborne platforms
Smart Structures
Health Monitoring
Inertial Monitoring Units
Sensors
Data Distribution
Subsystems Interconnect
Signal and Data Processing
Secure Comms
Airborne Radars
EW systems
….. in airborne platforms
Microwave
Photonics •
Optical
BFN
Waveform
Generator
Filtering
Antenna
remoting ,
Transponder
L.O.
generation/
distribution ……
Digital
Photonic
ADC &
wideband
digitizer
Computing … .
Fiber
Optic
Link
High data rate
interconnections
Secure
Comms
Sensors
Smart
structure
Homeland
security
Inertial
sensors (
gyro
acceler ., .)
Acoustic
Sensor
hydrophones
, ..)
Optoelectronic
Chemical /
Biological
Quantum
Optics
Cryptography
computers
comms
interconnect
In package Chip to
Chip
On board
Board ..

4. Photonics: where optic meets electronic ….. ….. in airborne platforms
BRAGG
GRATING
FIBER
OPTIC
TERMINATION
Airborne Radars
Navigation
Fire control
Smart Structures
Distributes fiber sensors
FBG
Health Monitoring
Structural
Engine
Human
Subsystems Interconnect
computers
sensors / actuators
weapons
fly-by-light
…..
Signal and Data Processing
Inertial Monitoring Units
gyroscope
Sensors
FLIR
wind shear
LIDAR / LOAS
Multi-Hyper Spectral
DIRCM / Designators
EW systems
ESM
ECM
Secure Comms
Data Interconnect

5. Why photonics ?
improved EM interference immunity
reduce volume and weight
huge digital data handling capability
low losses / low dispersion
wide instantaneous bandwidth
real time processing
high accuracy and resolution
…….

6. Health Management System
Structural Monitoring: FBG
Health Management System (HMS) & Health Monitoring Equipment (HME)
Impacts Revelation
Corrosion Revelation
Defects Revelation
Load monitoring
Strain Sensors
NDT +
Stress measure
Health Monitoring
Equipment
(HME)
Fatigue Life Analysis
Damage monitoring
PROGNOSIS
DIAGNOSIS
Health Management System
(HMS)
HMS on-board connected
to the ground support structure

7. Structural Monitoring: FBG
Fiber Optic Bragg Grating (FOBG)
AOTF PRINCIPLE
Bragg Law
AOTF
BRAGG
GRATING
FIBER
OPTIC
TERMINATION
Cobonded J-spar with embedded FOBG sensors
The sensorised fiber is embedded into the composite structure
Variations of the grating pitch  can be read (i.e. mechanical stress, thermal deformations, pressure variation, ice formation)
Several sensors can be positioned on the same fiber and separately
A multiplex fiber system can be realized

8. Structural Monitoring: FBG
PYLON HOUSING TEST BOX
Typhoon
Embedding of FOBG sensors into composite materials (carbon);
System integration and
ground test demonstration
Centre Fuselage
AREA A
Stringer 10
C27J
Frame 18
left side
AREA B
FORWARD

9. Gyro
Gyroscopes are key elements of IMU (Inertial Monitoring Units) in the navigation system of airborne platforms
Optical gyroscopes have no moving parts, then:
gravitation doesn’t affect
no need for gimbal mounting
reduced sensitivity to vibrations
insensitive to EM fields Ω
Splitter
Combiner
cw path
ccw path
Sagnac effect: rotation Ω induces phase shift ΔΦ between cw and ccw radiation paths
ΔΦ=4π Α•Ω / λc

10. Gyro Fiber optic gyroscope 0,01 deg/h
Can be produced in a smaller size in principle (looses precision though)

11. Gyro Gyro Technology Applications 103 102 10 1 10-1
STRATEGIC BALISTIC MISSILES
AUTONOMOUS SUBMARINE NAVIGATION
AIR/LAND/SEA NAVIGATION SURVEYING
AHRS TORPEDO
TACTICAL MISSILE MIDCOURSE GUIDANCE
FLIGHT CONTROL SMART MUNITIONS ROBOTICS
STRATEGIC CRUISE MISSILES
MECHANICAL
RING LASER
FIBER OPTIC
MEMS / MEOMS
Bias Stability (deg/h)
Scale Factor Stability (ppm)
1 nautical mile/hour
Earth rate
STRATEGIC
NAVIGATION
TACTICAL
CONSUMER
Gyro Technology Applications

12. Radar
Photonic solutions in Airborne Radar systems
Beam Forming networking in phased array active antennas
Time delay lines
Analog/Digital signal processing and distribution
Fiber optic massive data transmission systems
Very fast A/D converter
Parallel optical computing
Antenna remoting
Antenna calibration

13. Photonic Microwave Photonics Radar Digital Photonics
Frequency Generation
Photonic
a technology for advanced Radar and EW systems
Photonic ADC Converters
100 Gsample/s
BW >20 GHz
Resolution >8 bit
Fiber Optic Massive Data Transmission System
Antenna Remoting Trasponder
>100 Gbit/s per link
Photonic Digital Signal
Processor
Processor speed > 10 THz
Giga Multiply Acc. Op. per sec.
Filtering
Microwave Photonics
Optical BFN

14. Radar Four steps towards the Photonic Antenna System Step IV:
Step III:
Photonic replaces relevant parts of the RF system
Step IV:
Photonic assimilates the RF system TX RX
Step II:
Photonic implements
complex RF functions
Step I:
Photonic supports the RF system

15. Radar Analog to Digital conversion
Concepts of Photonic A/D conversion basically relies on using an optical architecture to:
Generate a stream of very low jitter sampling optical pulses + wavelength dispersion
Modulate the height of the dispersed optical pulses by the voltage signal to be sampled through an optical modulator
Split along multiple (N) parallel wavelength channels the samples
Perform A/D conv. in each channel with 1/N sampling
rate using std electronic A/DCs
Recombine the bit stream
by digital processing

16. Radar Frequency / Waveform Generations
Optoelectronic schemes and architectures for low phase noise RF oscillators at microwave frequencies (typ. 1 to 20 GHz) with high spectral purity (typ kHz offset for X band radar application)

17. Radar Optical Beam Forming in Phased Array Antennas
Antenna architecture for the beamforming (BFN) function, supporting simultaneous multiple RF functions and allowing for a dynamic reconfiguration of array elements
Analog RF and Digital control signals distributed by the same fiber network

18. Optical Interconnections
Due to continually shrinking feature sizes, higher clock frequencies, and the simultaneous growth in complexity, the role of interconnect as a dominant factor in determining circuit performance is growing in importance
Optical interconnects to mitigate the limitations of metal interconnects
on-chip
on-board
board to board

19. Optical Interconnections
sub-system to sub-system
“fly by light” the step beyond the “fly by wire”

20. Optical Interconnections
AFDX (Avionics Full-Duplex Switched Ethernet): Airbus implementation
Through the use of twisted pair or fiber optic cables, Full-Duplex Ethernet uses two separate pairs or strands for transmit and receiving data. AFDX extends standard Ethernet to provide high data integrity and deterministic timing

21. insertion into airborne platforms
New technological frontiers
New technologies
to support Photonics
insertion into airborne platforms
What ahead ?
Multifunctional low cost integration:
Hybrid Silicon Photonics
Functional Polymer Integrated Circuits
III-V Circuitry
New devices and sensors:
Photonic Band Gap
Nanophotonics
Plasmonics
New crossings with “electrons/electronics”:
THz

22. New technological frontiers
Multifunctional low cost integration:
Hybrid Silicon Photonics
Functional Polymers Integrated Circuits
III-V Circuitry

23. New technological frontiers
New devices and sensors:
Photonic Band Gap
Plasmonics

24. New technological frontiers
Nano Photonics

25. Conclusions
Photonic is a powerful underpinning technology in many avionic applications, enabling to advanced solutions and new capabilities
The use of COTS from the consumer communication market is accelerating the introduction of photonic solutions into aerospace platform
The most advanced photonic technologies are going to facilitate the photonic insertion into the aerospace platforms with their new multifunction integration capabilities and advanced functionalities.

26. Thank you for your attention
questions ?