Download Photonics

Photonic technologies for
aerospace applications
Mauro Varasi (Finmeccanica)
Roma - August 20th, 2008
Outlook
 Photonics: where optics meet electronics
 Why photonics
 Structural Monitoring: FBG
 Gyro
 Radar
 Data Links
 New technological frontiers
 Conclusions
Photonics: where optic meets electronic …..
….. in airborne platforms
Airborne
Radars
EW systems
Digital Photonics
Microwave Photonics
• Photonic ADC & wideband digitizer
• Optical Computing
• ….
• Optical BFN
• Waveform Generator
• Filtering
• Antenna remoting,
remoting, Transponder
• L.O. generation/distribution
generation/distribution
• ……
Inertial
Monitoring
Fiber Optic Sensors
Units • Smart
structure
Fiber Optic Link
Photonics
• Homeland security
• Inertial sensors (gyro,
gyro, acceler.,
acceler., ….)
• Acoustic Sensor (hydrophones,
hydrophones, ..)
• ….
Health
Monitoring
Signal and Data
Processing
Subsystems
Interconnect
Optoelectronic Sensors
• Chemical / Biological sensors
• Homeland security
• ….
Smart Structures
Sensors
• High data rate interconnections
• Secure Comms
• ….
Data
Distribution
Optical interconnect
• In package Chip to Chip
• On board
• Board to Board
• …..
Quantum Optics
• Cryptography
• Optical computers
• Secure comms
• ……
Secure
Comms
Photonics: where optic meets electronic …..
….. in airborne platforms
BRAGG
GRATING
FIBER
OPTIC
TERMINATION
Data
Interconnect
Health Monitoring
Subsystems
Interconnect
• computers
• sensors / actuators
• weapons
• fly-by-light
• …..
Smart Structures
• Distributes fiber
Sensors
sensors
• FBG
Inertial Monitoring Units
• gyroscope
• …..
• Structural
• Engine
• Human
• FLIR
• wind shear
• LIDAR / LOAS
• Multi-Hyper Spectral
• DIRCM / Designators
Signal and Data
Processing
Airborne Radars
EW systems
• ESM
• ECM
Secure Comms
• Navigation
• Fire control
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
 …….
Structural Monitoring: FBG
Health Management System (HMS) & Health Monitoring Equipment (HME)
Load monitoring
Strain Sensors
NDT
+
Stress measure
Impacts Revelation
Corrosion Revelation
Defects Revelation
Health Monitoring
Equipment
(HME)
Fatigue Life Analysis
PROGNOSIS
Damage monitoring
DIAGNOSIS
Health Management System
(HMS)
HMS on-board connected
to the ground support structure
Structural Monitoring: FBG
AOTF PRINCIPLE
Fiber Optic Bragg Grating (FOBG)
Bragg Law
AOTF
The sensorised fiber
composite structure
is
embedded
into
the
Variations of the grating pitch  can be read (i.e.
mechanical stress, thermal deformations, pressure
variation, ice formation)
BRAGG
GRATING
FIBER
OPTIC
TERMINATION
Several sensors can be positioned on the same
Cobonded J-spar with embedded FOBG senso
fiber and separately
A multiplex fiber system can be realized
Structural Monitoring: FBG
PYLON HOUSING
TEST BOX
Typhoon
•Embedding of FOBG sensors into
composite materials (carbon);
System
integration and
ground test
demonstration
Centre
Fuselage
Stringer 10
AREA A
C27J
Frame 18
left side
AREA B
FORWARD
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
Combiner
cw path
Ω
ccw path
Splitter
Sagnac effect: rotation Ω induces
phase shift ΔΦ between cw and ccw
radiation paths
ΔΦ=4π Α•Ω / λc
Gyro
Fiber optic gyroscope
• 0,01 deg/h
• Can be produced in a smaller
size in principle (looses precision
though)
Gyro
STRATEGIC
NAVIGATION
1 nautical mile/hour
103
Scale
Factor
Stability
(ppm)
FIBER
OPTIC
TACTICAL
CONSUMER
FLIGHT CONTROL
SMART MUNITIONS
ROBOTICS
TACTICAL MISSILE
MIDCOURSE GUIDANCE MEMS /
MEOMS
AHRS
TORPEDO
102
STRATEGIC CRUISE
MISSILES
STRATEGIC
BALISTIC
MISSILES
10
MECHANICAL
AIR/LAND/SEA
NAVIGATION
SURVEYING
Earth rate
AUTONOMOUS
SUBMARINE
NAVIGATION
1
Gyro
Technology
Applications
RING LASER
10-6
10-1
10-5
10-4
10-3
10-2
10-1
1
Bias Stability (deg/h)
10
102
103
104
105
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
Radar
Digital
Photonics
Photonic ADC
Converters
Fiber Optic Massive
Data Transmission
System

 
Y  AX  N
Photonic Digital
Signal
Processor
• 100 Gsample/s
• BW >20 GHz
• Resolution >8 bit
• >100 Gbit/s per link
Photonic
a technology for
advanced Radar
and EW systems
Frequency
Generation
Antenna Remoting
Trasponder
• Processor speed > 10 THz
• 10.000 Giga Multiply Acc. Op. per sec.
Filtering
Optical BFN
Microwave
Photonics
Radar
Four steps towards the Photonic Antenna System
RX
TX
Step IV:
Step III:
Step II:
Step I:
Photonic supports
the RF system
Photonic implements
complex RF functions
Photonic replaces
relevant parts of the
RF system
Photonic
assimilates the
RF system
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
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. -140 dBc/Hz @ 10 kHz offset for X band radar
application)
optical output
dual frequency
optical source
ampli. filter
photodiode
RF
splitter
fiber loop(s)
or
µ-sphere(s)
or
µ-disk(s)
Pump Laser
E/O Modulator
Optical_Out
RF output
Fiber
Spool
RF
Filter
RF_Out
RF
Sp lit te r
Photo
Detector
Optical
Path
E
l ec t ric a l Pa th
RF A mplifier
Radar
Optical Beam Forming in Phased Array Antennas
Optical MIR
Radar Rx
BFN
Optical MIR
EW Rx
BFN
Optical MIR
Control
Comms Rx
BFN
Optical MIR
•
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
Comms Rx
BFN
Optical Routing Switch
•
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
Optical Interconnections
sub-system to sub-system
“fly by light” the step beyond the “fly by wire”
Optical Interconnections
AFDX (Avionics Full-Duplex Switched Ethernet):
Airbus implementation
Through the use of
twisted pair or fiber
optic cables, FullDuplex Ethernet
uses two separate
pairs or strands for
transmit and
receiving data.
AFDX extends
standard Ethernet
to provide high
data integrity and
deterministic timing
New technological frontiers
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”:
Plasmonics
THz
New technological frontiers
Multifunctional low cost integration:
Hybrid Silicon Photonics
Functional Polymers Integrated Circuits
III-V Circuitry
New technological frontiers
New devices and sensors:
Photonic Band Gap
Plasmonics
New technological frontiers
Nano Photonics
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.