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Semiconductor Optical Amplifiers in Avionics. C Michie, W Johnstone , I Andonovic , E Murphy , H White, A Kelly. Semiconductor Optical Amplifiers in Avionics. Significant advantages within Avionics context from use of optical communications networks - PowerPoint PPT Presentation
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Semiconductor Optical Amplifiers in Avionics
C Michie, W Johnstone , I Andonovic , E Murphy , H White, A Kelly
Semiconductor Optical Amplifiers in Avionics
• Significant advantages within Avionics context from use of optical communications networks • bandwidth, EMI, significant weight savings
• Current systems limited to point to point, multimode
• This work• Learn from terrestrial communications using COTS• Focus on PONs – cost is critical• Strategies towards WDM – minimal component inventory
• Key operational consideration• Extended temperature range
Long Haul; DWDM systems maximise fibre bandwidth
usageTXλ1
TXλ2
TXλN
TXλX
TXλX
TXλX
TXλX
40 wavelengths, 200 GHz spacing10,40, 100+ Gbit/channel
Long Haul; DWDM systems maximise fibre bandwidth
usage• Wavelength specific transmitters
– single wavelength, DFB– Temperature regulated
• Many wavelengths– inventory issues for Avionic system
• Temperature Control– increased power consumption
• Expensive for Avionics– not a flier!
Passive Optical Networks
• High bandwidth Access solutions• Cost is critical – minimise number of components• Minimise manufacturing specification• Operate without cooling if possible
• Reflective Semiconductor Based Optical Amplifiers– RSOA – transmitter and amplifier using same
component
CS- RSOA
RSOAs as transmitters
User end
BLS
P
λ
P
λ
CS-RSOA
RSOAs as transmitters
User
Broad Band Source
P
λ
P
BLS
CS-RSOA
CS-RSOA
CS-RSOA
Avionics Link
• Simple link– 500 m, 1 Gbit/s
• Single Broad band seed source– might need two ?
• Multiplexer, de-multiplexer• Minimal cooling/heating
BLS
Fibre Link
Tx RSOA
Tx RSOA
Tx RSOA
Tx RSOA
Rx
Rx
Rx
Rx
Fibre Link Tx RSOA
Tx RSOA
Tx RSOA
Tx RSOA
Rx
Rx
Rx
Rx
0.6 dB
0.6 dB
0.8 dB3.5 dB
RSOA Design
InP:InGaAsPBuried HeterostructureLateral Waveguide TapersTensile Bulk
High back refectivity 0.88
Front facet AR coated
RSOA in TO
TO-packaged S-band RSOA TO-packaged S-band RSOA parametric testsparametric tests
Standard tests at 25ºC and 80mA
Dynamic Range
• Psat ~ 5 dBm, Gain > 20 dB• so we need -15 dBm input to saturate• Can get 0dBm/nm from COTS sources
• -5 dBm/nm is obtainable with lower power module– NB the above module needs to be cooled but it should
be the only component within the system• To get 12 dB dynamic range (allows 3dB plus of
margin) we can allow gain/Psat drop with temperature
RSOA modulation experimentsRSOA modulation experiments
TO packaged devices on ETS evaluation board50mA DC bias, 60mA modulation S band RSOA, CW injection at 1465 – 1530nmStage temperature 25°CModulation at 1.25 Gbps data rate with 211-1 PRBS bit patternThe Rx - APD photoreceiver with limiting amplifier
Sensitivity, Output Power, Gain and Path Sensitivity, Output Power, Gain and Path Loss Capability at 1490nm and 25Loss Capability at 1490nm and 25ºCºC
~30dB return path loss capability at -20dBm input
Sensitivity, Output Power, Gain and Path Sensitivity, Output Power, Gain and Path Loss Capability at 1580nm and 25Loss Capability at 1580nm and 25ºCºC
Sensitivity, Output Power, Gain and Sensitivity, Output Power, Gain and PLC versus Wavelength at 25PLC versus Wavelength at 25ºCºC
-20dBm CW input power and 25ºC stage temperatureEye diagram at 1490nm
S, C and L band performanceS-band device C-band device
-40
-30
-20
-10
0
10
20
30
40
1440 1460 1480 1500 1520 1540 1560 1580 1600 1620 1640
Wavelength (nm)
Se
ns
itiv
ity(d
Bm
),P
ou
t(d
Bm
),P
LC
(dB
),G
ain
(dB
)
Sens
Pout
Gain
PLC
RSOA with Broadband light source
Path Loss Capability TLS, BlS
0
5
10
15
20
25
30
35
40
-30 -25 -20 -15 -10 -5
Input Power (dBm)
Po
we
r B
ud
ge
t (d
B)
-35
-30
-25
-20
-15
-10
-5
0
Se
ns
itiv
ity
(dB
)
Margin BLS 0.5 nm
Margin TLS
BLS Sens 0.5 nm
TLS Sens
High Temperature RSOA Design
AlInGaAs Ridge WaveguideSingle Polarisation
High back refectivity 0.88
Front facet AR coated 0.01%
RSOA in TO
Temperature Performance of RSOA
TuneableLaser RSOA
OpticalSpectrum Analyser
VariableAttenuator
Temperature Controlled
Mount
Evaluate Gain, NF, Psat as a function of temperature.Enables prediction of performance(Power budget for BER 10-9)
Packaged BH Temperature Characterisation
Chip on CarrierRidge Temperature
Characterisation
Temperature Characterisation
Conclusions
• WDM PONs enabled by RSOAs–TO packaged polarisation insensitive S band RSOA – ~1dB penalty at 1.25Gbit/s compared to commercial M-Z modulator
• High Temperature OperationAlInGaAs active region
–Ridge waveguide design due to oxidation–Single polarisation –Potential to increase operating temperature to > 70 C–Much reduced cooling requirement