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

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

MicrowaveMicrowave PhotonicsPhotonics•• OpticalOptical BFNBFN•• WaveformWaveform GeneratorGenerator•• FilteringFiltering•• Antenna Antenna remotingremoting, , TransponderTransponder•• L.O.L.O. generation/generation/distributiondistribution•• …………

DigitalDigital PhotonicsPhotonics•• PhotonicPhotonic ADC & ADC & widebandwideband digitizerdigitizer•• OpticalOptical ComputingComputing•• ……..

FiberFiber OpticOptic LinkLink•• High data rate High data rate interconnectionsinterconnections•• SecureSecure CommsComms•• ……..

FiberFiber OpticOptic SensorsSensors•• Smart Smart structurestructure•• HomelandHomeland securitysecurity•• InertialInertial sensorssensors ((gyrogyro, , acceleracceler., ., …….).)•• AcousticAcoustic SensorSensor ((hydrophoneshydrophones, ..), ..)•• ……..

OptoelectronicOptoelectronic SensorsSensors•• ChemicalChemical / / BiologicalBiological sensorssensors•• HomelandHomeland securitysecurity•• ……..

Quantum Quantum

FiberFiber OpticOptic LinkLink•• High data rate High data rate interconnectionsinterconnections•• SecureSecure CommsComms•• ……..

FiberFiber OpticOptic SensorsSensors•• Smart Smart structurestructure•• HomelandHomeland securitysecurity•• InertialInertial sensorssensors ((gyrogyro, , acceleracceler., ., …….).)•• AcousticAcoustic SensorSensor ((hydrophoneshydrophones, ..), ..)•• ……..

FiberFiber OpticOptic SensorsSensors•• Smart Smart structurestructure•• HomelandHomeland securitysecurity•• InertialInertial sensorssensors ((gyrogyro, , acceleracceler., ., …….).)•• AcousticAcoustic SensorSensor ((hydrophoneshydrophones, ..), ..)•• ……..

OptoelectronicOptoelectronic SensorsSensors•• ChemicalChemical / / BiologicalBiological sensorssensors•• HomelandHomeland securitysecurity•• ……..

OptoelectronicOptoelectronic SensorsSensors•• ChemicalChemical / / BiologicalBiological sensorssensors•• HomelandHomeland securitysecurity• ……..

Quantum Quantum OpticsOptics•• CryptographyCryptography•• OpticalOptical computerscomputers•• SecureSecure commscomms•• …………

Quantum Quantum OpticsOptics•• CryptographyCryptography•• OpticalOptical computerscomputers•• SecureSecure commscomms• …………

OpticalOptical interconnectinterconnect•• In package Chip In package Chip toto ChipChip•• On board On board •• Board Board toto BoardBoard•• ……....

OpticalOptical interconnectinterconnect•• In package Chip In package Chip toto ChipChip•• On board On board •• Board Board toto BoardBoard•• ……....

PhotonicsPhotonics

Photonics: where optic meets electronic …..

Photonics: where optic meets electronic ….. ….. in airborne platforms

BRAGG

GRATING

FIBEROPTIC

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

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

Impacts RevelationCorrosion RevelationDefects Revelation

Impacts RevelationCorrosion RevelationDefects Revelation

Load monitoringStrain Sensors

Load monitoringStrain Sensors

Stress measureStress measure

Fatigue Life AnalysisFatigue Life Analysis

PROGNOSISPROGNOSISPROGNOSISPROGNOSIS

Damage monitoringDamage monitoring

DIAGNOSISDIAGNOSISDIAGNOSISDIAGNOSIS

HMS on-board connectedto the ground support structure

Health MonitoringEquipment

(HME)

Health MonitoringEquipment

(HME)

NDTNDT ++

Health Management System (HMS) & Health Monitoring Equipment (HME)

Health Management System(HMS)

Fiber Optic Bragg Grating (FOBG)

BRAGGGRATING

FIBEROPTICTERMINATION

Cobonded J-spar with embedded FOBG sensors

Bragg Law

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

AOTF PRINCIPLE

Structural Monitoring: FBG

AOTF

•Embedding of FOBG sensors into composite materials (carbon);

System integration and ground test demonstration

Frame 18 left side

FORWARD

Centre FuselageStringer 10 AREA A

AREA B

PYLON HOUSING TEST BOX

Typhoon

C27J

Structural Monitoring: FBG

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

Combinercw path

ccw pathΔΦ=4π Α•Ω / λc

Sagnac effect: rotation Ω induces phase shift ΔΦ between cw and ccw radiation paths

Gyro

Fiber optic gyroscope• 0,01 deg/h• Can be produced in a smaller

size in principle (looses precision though)

Gyro

103

102

10

1

10-1

10-6 10-5 10-4 10-3 10-2 10-1 1 10 102 103 104 105

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

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

Photonic solutions in Airborne Radar systems

Radar

PhotonicPhotonic

a technology for a technology for advanced Radar advanced Radar and EW systemsand EW systems NXAY

Photonic ADC Photonic ADC ConvertersConverters

Fiber Optic Massive Fiber Optic Massive Data Transmission Data Transmission

SystemSystem

Photonic Digital Photonic Digital SignalSignal

ProcessorProcessor

• 100 Gsample/s100 Gsample/s• BW >20 GHzBW >20 GHz• Resolution >8 bitResolution >8 bit

• >100 Gbit/s per link100 Gbit/s per link

• Processor speed > 10 THzProcessor speed > 10 THz• 10.000 Giga Multiply Acc. Op. per sec.10.000 Giga Multiply Acc. Op. per sec.

Digital Digital PhotonicsPhotonics

Optical BFNOptical BFN

Frequency Frequency GenerationGeneration

FilteringFiltering

Microwave Microwave PhotonicsPhotonics

Antenna Remoting Antenna Remoting TrasponderTrasponder

Step IV: Step IV:

Photonic Photonic assimilates the assimilates the RF systemRF system

TXTX

RXRX

Step III: Step III:

Photonic replaces Photonic replaces relevant parts of the relevant parts of the RF systemRF system

Step II: Step II:

Photonic implementsPhotonic implements complex RF functions complex RF functions

Step I: Step I:

Photonic supports Photonic supports the RF systemthe RF system

Radar Four steps towards the Photonic Antenna System

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 Analog to Digital conversion

Radar Frequency / Waveform Generations

RF output

optical output

fiber loop(s)orµ-sphere(s)orµ-disk(s)

photodiodefilterampli.

RFsplitter

dual frequency optical source

RF output

optical output

fiber loop(s)orµ-sphere(s)orµ-disk(s)

photodiodefilterampli.

RFsplitter

dual frequency optical source

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)

Fiber Spool

RF Splitter

Optical_Out

E/O Modulator Pump Laser

RF Amplifier

RF_Out

RF Filter

Photo Detector

Fiber Spool

RF

Optical_Out

Optical Path Optical Path Electrical Path

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

Radar Rx

EW Rx

Comms Rx

Comms Rx

Op

tica

l M

IRO

pti

cal M

IRO

pti

cal M

IRO

pti

cal M

IR

BFN

BFN

BFN

BFN

Op

tica

l R

ou

tin

g S

wit

ch

Control

on-chip

on-board

board to board

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

Optical Interconnections

sub-system to sub-system“fly by light” the step beyond the “fly by wire”

AFDX (Avionics Full-Duplex Switched Ethernet): Airbus implementation

Optical Interconnections

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

New technological frontiers

What ahead ?

Multifunctional low cost integration: Hybrid Silicon Photonics

Functional Polymer Integrated CircuitsIII-V Circuitry

New devices and sensors:Photonic Band GapNanophotonicsPlasmonics

New crossings with “electrons/electronics”:PlasmonicsTHz

New technologies

to support

Photonics

insertion in

to airb

orne

platform

s

Multifunctional low cost integration:

Hybrid Silicon Photonics

Functional Polymers Integrated Circuits

III-V Circuitry

New technological frontiers

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.