Semiconductor Optical Amplifiers For Passive Optical Networks
Leo Spiekman, David PiehlerAlphion Corp.Semiconductor Optical Amplifiersfor Passive Optical Networks
focus of this talkLeo Spiekman, David Piehler, Alphion Corp. – November 2006 SOAs EDFAs (and other fiber amplifiers) Raman Amplifiers– FEC– Optical amplification PIN, APD– Receiver sensitivity Direct modulation, external modulation– Transmitter optical power / dispersion toleranceToolkit:Expanding the PON link budget2
110012001300Wavelength140015001600 nmEDFA Bandwidth 4 THz3 Based on ubiquitous InPtelecom technology Lower output power Operates at all telco laserwavelengthsLeo Spiekman, David Piehler, Alphion Corp. – November 200601 Ubiquitous in opticalcommunications High output power Only operates in the 1550nm bandEDFAs vs. SOAs for PONs
Leo Spiekman, David Piehler, Alphion Corp. – November 2006– Economies of integration– Each amplifier has 80 nm BW– Covers all wavelengths used in PONand CWDM– Amplification at any desired λ in range1200 1650 nmKey advantage:– Cost comparable to EDFA pump laser– Industry standard butterfly packaging– Chip is essentially an anti-reflectioncoated FP laserMature technology:Semiconductor Optical Amplifier4
OLTRxOLTTxSOAIn-lineSOA1xNsplitLeo Spiekman, David Piehler, Alphion Corp. – November 2006SOApre ampboosterSOA1xNsplitFor the purposes of this talk we consider the SOA asan OLT booster or preamp, or as an inline amp.SOAs in PONsONTTxONTRx5
Signal InLensChipOutput FiberSignal OutLensActive LayerLeo Spiekman, David Piehler, Alphion Corp. – November 2006 Buried hetero-structure Multi-quantum-well (shown) or bulk active layer Extremely low facet reflection: 10-4– Angled stripes, Anti-reflection coatingsInput FiberIfPackaging of SOA chip6
HolesWaveguide Core:InGaAsPAmplifiedLightLeo Spiekman, David Piehler, Alphion Corp. – November 2006 Stimulated emission around bandgap wavelength of semiconductor Bandgap wavelength widely tunable with material compositionWaveguide Cladding:InPCurrentSourceElectronsOperating Principle7
500 µmLeo Spiekman, David Piehler, Alphion Corp. – November 2006900 µmSOA Chip8
Leo Spiekman, David Piehler, Alphion Corp. – November 2006Many SOA chips in a unit cell 9
Leo Spiekman, David Piehler, Alphion Corp. – November 2006 many unit cells on a wafer10
Leo Spiekman, David Piehler, Alphion Corp. – November 2006Link performance impacted by: Gain Noise Figure Output Power ASE SpectrumSOA optical properties11
Power Spectral Density [dB/nm]-40-35-30-25-20-15-10-50Leo Spiekman, David Piehler, Alphion Corp. – November 2006Wavelength [nm]1240 1260 1280 1300 1320 1340 1360 1380 1400Amplified Spontaneous Emission12
Gain / NF [dB]14701490150015101520Wavelength [nm]Leo Spiekman, David Piehler, Alphion Corp. – November 20061480 Theoretical limit 3 dB13nsp population inversion factorη fiber-chip coupling efficiency0 PDG of 0.5 dB can nowroutinely be achieved 3-dB gain bandwidthapprox. 80 nm NF 2 nsp/ηTE GainTM GainTE NFTM NF Smooth parabolic gainshape thanks tosemiconductor bands5101520SOA Gain, PDG, NF
Polarization Dependence-3.0-2.5-2.0-1.5-1.0-0.50.00.51.0Leo Spiekman, David Piehler, Alphion Corp. – November 2006Increasing Tensile Strain -- 14– Tensile strainedQuantum Wells– Alternating Tensile/CompressiveQuantum Wells– Tensile Bulk Layer Polarization independent gain not automatic(unlike EDFA, SOA waveguide not rotationally symmetric) Use of strain in crystal to obtain polarization independencePolarization dependence (dB)
Gain [dB]051015202530-25-2010Psat153 dB15 But: saturation and gainrecovery occur on muchfaster timescale than inan EDFA, potentiallyleading to patterningeffects At large powers, theSOA gain saturates, justlike any other amplifierLeo Spiekman, David Piehler, Alphion Corp. – November 2006-15 -10 -505Output Power [dBm](Quasi-) Linear RegimeSOA Gain Saturation
SOAFilterλ2StreakCamera-6-200-4-20200400Time (ps)τ 140 ps600Leo Spiekman, David Piehler, Alphion Corp. – November 2006 Gain dynamics measurement using pump-probe technique Gain compression almost instantaneous Gain recovery of order of bit period for 10 Gb/s dataCW, λ2Mode LockedLaser, λ10Gain dynamicsGain Compression (dB)80016
linearLeo Spiekman, David Piehler, Alphion Corp. – November 200617 Typical available outputpower: 10 dBm Higher power available formore injection currentJ. J. J.Crijns, et al., Photon. Tech. Lett., 14, 1481 (2002)EDFASOABurst data:saturated– Limits operation to nonsaturated regime– But beneficial for burst data Essential difference SOAEDFA: gain dynamicsultrafastUse as Booster: Output Power
Leo Spiekman, David Piehler, Alphion Corp. – November 2006– The optical filter– The wavelength stability specification of thetransmitter18 Depending on the situation, the ASE emitted bythe SOA can impact the sensitivity of thereceiver Filtering this noise with an optical band passfilter improves performance at the cost ofASE filtering
A filter this narrowrequires wavelength(temperature) controlof the transmitterLeo Spiekman, David Piehler, Alphion Corp. – November 200610 Gb/s results.Sensitivity improvement over pindiode depends on width of BPF.Note: result shown with a 8-dBNF SOA.Sensitivity of -30 dBm at a BERof 10-9 for 10 Gb/s CWDM preamplifier.No filter at all (for 1260 – 1360nm case): still 7 dB improvementover bare pin.An uncontrolled,uncooled DFB canmaintain thiswavelength rangeUse as Pre-Amplifier:Noise Figure and ASE filtering19
Leo Spiekman, David Piehler, Alphion Corp. – November 200620 The optical filter bandwidth will have an impacton the wavelength spec on the transmitter This does not account for burst penalty SOA PIN should give equal absolute sensitivityto SOA APD– 7 dB if no optical filter is used– 10 dB if a 10 nm optical filter is used– 13 dB if a 1 nm optical filter is used An SOA pre-amp can improve a 10 Gb/s PINsensitivity bySOA preamplifier
P1-PpaSOAL1 (dB)ONTRx(PIN)Leo Spiekman, David Piehler, Alphion Corp. – November 200621P1 ONT optical powerPpa sensitivity of SOA PIN RxPpin sensitivity of PIN RxPout max output power of SOAG gain of SOAL link budget without SOAL2limited by SOA noise figure andoptical filter widthL1We need to operate inside green areaPout-Ppinlimited bySOA gainONTTxL1 L2 G Llimited bySOA powerL2 (dB)SOA as an in-line amplifier
Pase,fwdPase,revASE peakGain ripplePDGNFPsat (3-dB)Psat (1-dB) 0.10.110.020.090.10.10.03Leo Spiekman, David Piehler, Alphion Corp. – November 2006-8.7-8.914940.170.834.914.611.3Example SOA PerformancedBmdBmnmdBdBdBdBmdBm22
Leo Spiekman, David Piehler, Alphion Corp. – November 2006– Booster for downstream (req high Pout)– Pre-amp for upstream (req low NF) For amplifier located at OLT: moderate requirement on both NF, Pout and G Optimal location is mid-spanUse of amplifier in PON23
photodiode2x2tapcoupler 1310 nm1490 nm 1310 nm1555/(1490,1310)WDM 1310 nm1490 nm 1490 nm 1310/1490WDMSOAcontrolelectronics 1310 nmBPFSOABPFphotodiode 1310 nm1310/1490WDM 1310 nm1490 nm Leo Spiekman, David Piehler, Alphion Corp. – November 2006photodiode 1310 nm1490 nm 1490 nm external video optical amplifier (EDFA) (optional)1550 nm 1310 nm1490 nm 241490 nm 1555/(1490,1310)WDMphotodiode 1310 nm1490 nm 2x22x2fusedtapfibercouplercouplerPON Extension Module
AmplifiedCentralOfficeOLT149013101550 RF30 km Capability60 km CapabilityPON Line Amp Block149013101550 RFLeo Spiekman, David Piehler, Alphion Corp. – November 20064-Channel SOA2-Channel SOACoreCentralOffice(OLT)(Remote CO)Multi-Channel SOAONTONU25ONTONU
λ81BPFvar.attLeo Spiekman, David Piehler, Alphion Corp. – November 2006receiverBPF SOAdecorrelating4 km 8 x 10 Gb/s WDM 6 SOA-amplified spans 240 km total distance 40 km SSMF DCFmodulator1558-1570 nm10 Gb/sλIs WDM Possible?26
log (error hed power per channel [dBm] 0.5 1.5 dB power penalty 10 dB launched power tolerance-0.100.10.20.3Leo Spiekman, David Piehler, Alphion Corp. – November 200627(L.H. Spiekman et al., Photon. Technol. Lett. 12(8), pp. 1082-4, 2000)-29-27-25received power [dBm]baseline240 km20 ps/div0.40.50.68 x 10 Gb/s WDM over 240 kmBER penalty change [dB]
-601500-50-40-30-20-100101520Wavelength [nm]1540Output Power1560SOA Optical AmplifierLinearEDFA158035 dB14501490Back to back-40-30-20-1001570 SOALeo Spiekman, David Piehler, Alphion Corp. – November 200628161050 km AllWaveλ [nm]1530Spectrum after 50 km fiber SOAH. J. Thiele et al., OFC 2003, paper MF21.No indication of eye distortion due to crossgain modulationOutput Power [dBm/nm]Use of SOA in CWDM-PONdBm
R1RCVR2APDsC-BandDWDMUpgradeRCVR8(P.P. Iannone et al., OFC 2003, paper ThQ3)29 Eight CWDM channels amplified by asingle SOA Upgrade by replacing middle CWDMchannel with 8 DWDM channels.SOA60 kmLiNbO3 70 kmMODLeo Spiekman, David Piehler, Alphion Corp. – November 2006Wavelength (nm)1540Upgradeλ814701490CWDM -60-40-200λ1λ2C-BandDWDMTaking Advantage of Broad SOAGain Bandwidth Power (dBm)
Leo Spiekman, David Piehler, Alphion Corp. – November 2006 High contrast ( 40 dB) Fast ( ns)I 0 mAI 250 mAER 50 dBSOA as a data modulator30
Can also beconfigured asreflective SOA:single fiber to ONUES J1ES (J 1)1λ1λ2AN 2λNλ1ES 12ES 1Nλ2P. Iannone, et al., J. Lightwave Tech., 18, 1955 (2000).DATAAccessNode 1AN NWGRLeo Spiekman, David Piehler, Alphion Corp. – November 2006RxSOAModES 21λ1EndStation 11,λλ1,λ N ,2NetworkNodeEnd Station DetailDmuxMuxNetwork NodeDetailRx’sR1 R2Tx’sλ1 λ2Access Node DetailWavelength-agnostic example inan access network31
5 Gb/sLeo Spiekman, David Piehler, Alphion Corp. – November 200632(I.Tafur Monroy et al., Optics Express 14(18), pp. 8060-4, 2006) Single fiber connection Cheap packaging (TO-can) Currently assumed to beexternally cooledReflective SOA
Leo Spiekman, David Piehler, Alphion Corp. – November 2006 Amplification in access allows system marginenhancement SOA is a candidate technology with a high level ofmaturity Booster allows operation up to at least 10 dBm Pre-amplifier increases margin wrt. PIN by 7 – 13 dB,depending on whether filter is permitted In-line amplifier can extend distance and split ratio. Key advantage is that present PON wavelengthassignments are supported Growth path towards CWDM-PON availableSummary33
Semiconductor Optical Amplifiers for Passive Optical Networks Leo Spiekman, David Piehler Alphion Corp. 2 Expanding the PON link budget Leo Spiekman, David Piehler, Alphion Corp. – November 2006 Toolkit: – Transmitter optical power / dispersion tolerance Direct modulation, external modulation – Receiver sensitivity
Semiconductor Optical Amplifiers 9.1 Basic Structure of Semiconductor Optical Amplifiers (SOAs) 9.1.1 Introduction: Semiconductor optical amplifiers (SOAs), as the name suggests, are used to amplify optical signals. A typical structure of a InGaAsP/InP SOA is shown in the Figure below. The basic structure consists of a heterostructure pin junction.File Size: 1MB
Semiconductor Optical Amplifiers (SOAs) have mainly found application in optical telecommunication networks for optical signal regeneration, wavelength switching or wavelength conversion. The objective of this paper is to report the use of semiconductor optical amplifiers for optical sensing taking into account their optical bistable properties .
optical networks have been made possible by the optical amplifier. Optical amplifiers can be divided into two classes: optical fibre amplifiers (OFA) and semiconductor optical amplifiers (SOAs). The former has tended to dominate conventional system applications such as in-line amplification used to compensate for fibre losses.
Semiconductor optical amplifiers (SOAs) Fiber Raman and Brillouin amplifiers Rare earth doped fiber amplifiers (erbium – EDFA 1500 nm, praseodymium – PDFA 1300 nm) The most practical optical amplifiers to date include the SOA and EDFA types. New pumping methods and materials are also improving the performance of Raman amplifiers. 3
A. Borghesani, “Semiconductor optical amplifiers for advanced optical applications,” International Conference on Transparent Optical Networks, ICTON 2006, 119–122. 26. A. V. Uskov, T. W. Berg, and J. Mørk, “Theory of pulse-train amplification without patterning effects in quantum-dot semiconductor optical amplifiers,” IEEE J. Quantum .
51.3 Types of Semiconductor Optical Amplifiers SOAs can be classified as either subthreshold or gain clamped. Subthreshold amplifiers are lasers operated below threshold, and gain-clamped amplifiers are lasers operated above threshold but used as amplifiers. Subthreshold SOAs can be further classified according to whether optical feedback .
RF/IF Differential Amplifiers 5 Low Noise Amplifiers 7 Low Phase Noise Amplifiers 10 Gain Blocks 11 Driver Amplifiers 13 Wideband Distributed Amplifiers 13 Power Amplifiers 15 GaN Power Amplifiers 18 Variable Gain Amplifiers 19 Analog Controlled VGAs 19 Digitally Controlled VGAs 20 Baseband Programmable VGA Filters 21 Attenuators 22
reading is to read each day for at minimum 30 minutes. Please turn in all assignments to your child’s teacher in the fall. May you have a blessed, restful, relaxing, enjoyable and fun-filled summer! Sincerely, Thomas Schroeder & Vicki Flournoy Second Grade Summer Learning Packet. DEAR FAMILY, As many of you are planning for your summer activities for your children, we want you to remember .
