Journée scientifique de la chaire UPsud/PSA «Optoélectronique et Photonique» Circuits Photoniques Intégrés pour les Applications en Communications Optiques Guang-Hua DUAN III-V Lab, a joint lab of 'Alcatel-Lucent Bell Labs France', 'Thales Research and Technology' and 'CEA Leti', Campus Polytechnique, 1, Avenue A. Fresnel, 91767 Palaiseau cedex, France 5 Juin 2014
What is III-V Lab? A jointly owned Alcatel-Lucent Bell Labs / Thales Research & Technology /CEA R&D Lab LETI French GIE (Groupement d Intérêt Economique) organization with about 150 R&D experts (incl. 25 from CEA-Leti + ~18 PhD students) Dedicated to epitaxial growth, device and circuit design and manufacturing performing R&T on III-V semiconductor technology and integration with Si circuits and microsystems Optoelectronic and microelectronic materials, devices and circuits From basic research to technology transfer for industrialisation or to small scale and pilot line production for complementary Alcatel-Lucent / Thales applications High bit rate Optical Fibre and Wireless Telecommunications Microwave and Photonic systems for Defence, Security and Space Page 2
Outline Motivation Current state of art of III-V and silicon PICs InPbased PICs Silicon based PICs Comparison of InPPICs and silicon PICs Hybrid III-V/Si integration technology Future directions Page 3
Optical communication market segments and key components /key techniques VCSEL: low power consumption Parallel links Directly Modulated Lasers (DML) : low cost, low temperature sensitivity, low chirp Electro-absorption Modulated Lasers (EML) Wavelength division multiplexing 100 m 10 km Data communications Up to 25 Gb/s Acces networks Up to 10 Gb/s per λ Metro networks Up to 100 Gb/s per λ Tunable lasers over C band Wavelength division multiplexing QPSK modulators/coherent detection 100 km Core networks Up to 400 Gb/s per λ Page 4
Short-reachreach opticaltransceivers 29 Juin 2011 Page 5
Transmission WDM 2 Atténuation (db/km) 1 0 1,45 1,46 1,48 1,55 1,60 1,65 1,80 Longueur d onde (µm) λ 1 λ i λ k λ N 1530 40 50 60 1570 λ (nm) bande passante des amplificateurs optiques Longueur d onde (nm)
Wavelength Division Multiplexing WDM transmitter laser modulator λ1 laser modulator λ2 Wavelength multiplexer laser modulator λn WDM receiver Photodiode λ1 Photodiode Photodiode λ2 λn Wavelength multiplexer
Metro-long haul transceiver 29 Juin 2011 Page 8
Evolution of Coherent Transceiver Module 29 Juin 2011 Page 9
Photonic Integrated Circuits 100 Gb/s Transmit 100Gb/s Transmit 100Gb/s Receive 100 Gb/s Receive Courtery from Infinera
PIC: an on-going (r)evolution WDM transmitter laser modulator λ1 laser modulator λ2 Wavelength multiplexer laser modulator λn Photonic Integration Small footprint Cost effective Reduced power consumption High device yield Trade-off on performance
Intégration monolithic sur InP Butt-joint par une reprise de croissance Guide actif laser Guide passif Mux
CWDM : intégration de 4 et 8 λ par SAG Principe de la SAG : compositions + effet latéral X Ga 0.40 In 0.60 As Ga 0.50 In 0.50 As épaisseur x 2.5 200 nm Substrat
Masque 8 λà 20 nm CWDM : intégration de 4 et 8 λ par SAG λ 1 Wm 1 1550 1500 λ 2 Wm 2 λ (nm) 1450 1400 λ=160 nm 1350 Wm i 1300 0 20 40 60 80 100 120 140 160 180 Wm (µm) λ i dielectric
100 G PIC from Infinera Laser- modulator Laser- modulator Laser- modulator λ1 λ2 λn Wavelength multiplexer
Produit visé PIC 10x10G TOSA Sous-module optique Isolateur, wavelength locker Élément Peltier Substrat céramique multi-couches avec 10 drivers (éloignés du PIC) AWG flip-chippé Embase Si Barrette 10 lasers flipchippée
PIC: Detailed Comparison Power consumption: 30% less than 10xXFP Footprint reduction compared to discrete solution: 68% less than 10xXFP+Mux/Demux Lower cost: 7.6 k$ in 2011 and 5.2 k$ in 2012 compared to 13.7 k$ for 10xXFP+Mux/Demux Comparison between ALU PIC and Infinera PIC ALU PIC Power Consumption (28W) Reach: Unamplified links up to 70 km higher Tx output power (DML approach + Silica AWG) higher sensitivity (APD based Rx) Infinera PIC Power Consumption (48W) Reach: Unamplified links <10km lower Tx output power (EML approach + InP AWG) lower sensitivity (PIN based Rx)
PIC for QPSK transmitter Infinera s QPSK transmitter: PM DFB Nested MZM Bell Lab s QPSK/QAM Source Integration of tunable laser and Electro-absorption Modulators I. Kang, Optics Express 2007, C. Kazmierski, OFC 2014 Page 18
Roadmap of Infinera s PICs 100 elements 40 elements 40 elements From R. Dodd, Infinera Page 19
Photonic integrated circuits on silicon CMOS EIC platform on silicon Mature industrial process with high yield Foundry model for cost-effective industrial production Cost-effective for large volume PICs on silicon Taking benefit for EICs: industrial tools, foundry models, etc. Co-integration with CMOS electronics, close proximity between signal processing unit and photonic elements Providing optical interconnect solutions for More than Moore for EICs Can silicon be a Photonic integration platform?
The building blocks Optical modulator Photodetector MUX & DEMUX Waveguide Laser source Grating coupler In-plane coupler Optical switch
Impossible d'afficher l'image. Votre ordinateur manque peut-être de mémoire pour ouvrir l'image ou l'image est endommagée. Redémarrez l'ordinateur, puis ouvrez à nouveau le fichier. Si le x rouge est toujours affiché, vous devrez peut-être supprimer l'image avant de la réinsérer. Wafer level testing
Luxtera sactive Optical Cables Luxtera technology for transceiver Freescale SC Hip7 0.13µm SOI CMOS process Customized SOI & CMOS 130nm technology Proprietary library for electronic design Flip chip laser die bonding Si lateral depletion modulator 10Gb/s Ge photodetectors 20GHz Surface holographic gratings fiber coupling 4x28 Gb/s using 4 parallel links Luxtera and STMicroelectronics to Enable High- Volume Silicon Photonics Solutions Collaboration between two leading companies will bring silicon photonics into mainstream markets March 1 st, 2012 29 Juin 2011 Page 23
Single-chip 100 G Si transceiver Chip C. Doerre, et al., OFC 2014 27x35.5 mm2 module: PIC, Drivers and TIA Silicon PIC: 2.7x11.5 mm2 Page 24
Photonic Integration : InPvs vssi Photonics Platforms InP platform Si-photonics platform Functionality Performance Footprint Source, Detector, Waveguide, Modulator Excellent optical performance No large scale integration with electronics Large for passive elements (AWG, ring resonators, etc) Detector, Waveguide, Modulator Massive electronic integration No source: need for InP heterointegration or Ge sources Good optical performance Large scale integration with electronics for free Compact for passive elements (AWG, ring resonators, etc) Cost Power consumption Higher due to individual device testing, Low yield for PICs Low for electro-absorption modulator, higher for Mach-Zehnder type modulator Wafer scale testing CMOS processing & monitoring for free Foundry model for volume production will drive cost down Novel modulator design results in low drive voltage
Our Vision on Silicon PICs Silicon photonics approach: Mature CMOS fabrication process Available key building blocks: modulators, detectors, low loss passive waveguides, wavelength multiplexers/demultiplexers Lack of efficient lasers sources on silicon Sources for silicon photonics Geon silicon lasers and Epitaxyof III-V layers on silicon through a buffer layers: very promising results, but still requiring developments Hybrid III-V/Si integration using wafer bodning: most efficient solution today Hybrid III-V/Si integration combing advantages of III-V and Si III-V: providing optical gain Si: providing wavelength selection and tuning using passive silicon waveguides Dies to wafer or wafer to wafer bonding proven to be a reliable process for SOI wafers => a new classeof tunablelasers with large tuning range, high SMSR and compact size = > PIC transmitter integrating tunablelasers and silicon modulators Page 26
Heterogeneous integration Growth of the III- V wafers III-V die or wafer bonding on SOI (unprocessed) InP substrate removal Processing of SOI wafers (modulators, detectors, passive waveguides, etc.) Processing of III-V dies/wafer Metallization of lasers, modulators and detectors
Growth of III-V wafers for hybrid integration Growth of active layer in a reverse order compared to classical InP devices Example of a 6 QW MBE grown wafer InP (n) SCH MQW SCH InP (p) cladding InGaAs contact Substrate Strained MQW InGaAsP/InP for 1.3 and 1.5 µm operation using MBE Strained MQW InGaAlAs/InP for 1.3 operation using MOVPE Page 28
Processing of SOI wafers SOI substrate 1-Processed SOI substrate: etching and implantation of silicon waveguide Typicalthicknessof siliconwaveguidesfor couplingwithiii-v waveguidesbetween400 and 500 nm 2- PECVD silica deposition 3- CMP planarization Typical thickness of silica above RIB silicon waveguide between 30 and 100 nm Page 29
III-V / Si heterogeneous integration: wafer bonding SOI wafer Low temperature bonding III-V heterostructure PECVD silica deposition Thin layer 10 nm (roughness < 0.5 nm RMS) Annealing and Substrate removal Page 30
Bonded III-V wafers/dies on SOI Wafer to wafer bonding Dies to wafer bonding Page 31
Bonding of III-V dies on SOI wafer III-V dies SiO2 BOX Si waveguide
Laser cutting of 8 wafers into 3 wafers, ready to be processed in a III-V foundry Processing of III-V lasers on silicon
Hybrid laser structure M. Lamponi, et al., IEEE PTL, Jan. 2012 Straight active section, typically 2-3µm width, for optical amplification Passive SOI rib waveguides Double taper structure for both InP and Si waveguides or single taper structure for Si waveguide to efficiently couple light from III-V to silicon
Power vs current of a Fabry-Perot sample at 1.3 µm (InGaAlAs/InP) Threshold current of 12mA at room temperature for 500 µm devices Maximum out power at 20 C: 10 mwat CW conditions and 16 mwfor I = 150 maat pulse conditions Operating up to 80 at CW conditions Still reflections in the III-V/Si waveguide transition areas Page 35
Power vscurrent of a Fabry-Perot sample at 1.5 µm (InGaAsP/InP) Photodiode coupled output power (mw) 14 12 10 8 6 4 2 15 C 20 C 30 C 40 C 50 C 60 C 70 C 80 C 0 0 50 100 150 Current (ma) 200 Threshold current: 23mA at room temperature for 800 µm devices Maximum out power at 20 C: 18 mwat CW conditions Operating up to 65 at CW conditions Still reflections in the III-V/Si waveguide transition areas Page 36
Tunablelasers with 45 nm tuning range Heater/Ring resonator 2 Gain section Heater/Ring resonator 1 Grating coupler A. Le Liepvre, et al., GFP Conference, Aug. 2012
Wavelength selectable laser Wavelength selectable source : Si AWG inside the laser cavityas a filter Broadband bragg reflectors for feedback Si AWG : 5 channels, 400GHz spacing Vertical bragggratingsfor on wafer scale testing Simple wavelength tuning for access networks Can also be used as multiwavelength source Page 38
Wavelengthselectablelaser laser : spectrum Spectrum for each channel with 110mA injection Single mode operationwith > 30 db SMSR 390GHz spacing between channels 0 Power coupled to fibre (dbm) 0-10 -20-30 -40-50 -60-70 -80 1514 1516 1518 1520 1522 1524 Wavelength (nm) Power coupled in fibre (dbm) -10-20 L5 I=110mA L4 I=110mA -30 L3 I=110mA L2 I=110mA -40 L1 I=110mA -50-60 -70-80 1480 1500 1520 1540 1560 1580 1600 Wavelength (nm) Spectrum for each channel Page 39
Tunable transmitter chip Back Bragg reflector III-V waveguide Hybrid III-V/Si laser Front Bragg reflector Silicon MZ modulator Output waveguide Laser Ring resonator Mach-Zehnder Modulator G. H. Duan, et al., ECOC 2012 Page 40
BER and eye diagrammeat at 10 Gb/s Log(BER) -2-3 -4-5 -6 Ref. λ1 λ2 λ3 λ4 λ5 λ6 λ7 λ8-7 -8-9 -10-32 -30-28 -26-24 -22-20 -18-16 Received Power (dbm) λ1 λ3 λ5 λ7 λ2 λ4 λ6 λ8 Page 41
Technology roadmap Demonstrators 4x25G Active optical cable 4x100 G WDM transceiver 2 Tb/s WDM transceivesr Optical Network on Chip Design & integration Photonic PDK Photonic Electronic integration Photonic IP libraries Complete Design flow Building blocks Avalanche photodiode High temperature laser Low power 40G modulator Plasmonics 2013 2015 2017
Acknowledgements European projects: Plat4M, Fabulous, Sequoia French national projects: ANR Ultimate (QPSK QAM transmitter) III-V Lab: A. Accard, P. Kaspar, F. Poingt, D. Make, F. Lelarge, G. Levaufre, N. Girard, C. Jany, A. Le Liepvre, M. Lamponi, A. Shen, R. Brenot, F. Mallecot CEA: S. Olivier, S. Malhuitre, S. Messaoudene, D. Bordel, and J.-M. Fedeli, C Kopp, B. Ben Bakir, L. Fulbert IEF: L. Vivien, D. Morini Page 43