Low Power DSP and Photonic Integration in Optical Networks. Atul Srivastava CTO, NTT Electronics - America. Market Focus ECOC 2014

Transcription

1 Low Power DSP and Photonic Integration in Optical Networks Atul Srivastava CTO, NTT Electronics - America Market Focus ECOC 2014

2 Outline 100G Deployment Rapid Growth in Long Haul Role of Modules New Low Power 100G DSP Based on 20nm CMOS Versatile: Many Applications Pluggable Modules (CFP, CFP2 ) Integration in Optical Components InP Devices Si Photonics Compact Tx/Rx with DSP assist Discussion 2

3 100G Deployment Trends Exponential Growth: Doubling years 3

4 100G Coherent Metro Networks Long-Haul Long-Haul >1500, 6-8 ROADMs Metro Regional Metro-Regional km; 16 ROADMs Metro Core Metro-Core km; 24 ROADMs Metro Access Metro-Access km Typical Optical Specs: 16dB OSNR, 15,000ps/nm dispersion, 12ps PMD Cost, Power and Size of module are key metrics for 100G Metro 4

5 100G Modules and Line cards: Lower Power and Smaller Size Enabling higher card density Power Consumption 100W Module Power dominated by electronic components Lower Power DSP 45W OIF Gen 1 5x7 MSA 80W OIF Gen 2 4x5 MSA 45W CFP <30W CFP2 ACO 12W Module Size determined by optical components Tx & Rx More Integration Size (Smaller) 5

6 100G Transceiver Module/DSP Power Dissipation 5 x7 CFP 4 x5 40nm CMOS 20nm 28nm 6

7 Mod. Mod. Mod. Trends on Coherent Transceiver MSAs ~2017 DSP DSP Rx Rx 4 x5 OIF Gen-2 IA Editor: Atul Srivastava 5 x7 Long-haul, telecom Multi-haul, Telecom DSP CFP2 ACO Rx CFP DSP NEL DSPs Gen-1 Gen-2 Non-LH Telecom/Datacom 7

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9 NLD G DSP 40-nm CMOS External transmit MUX, external framer ASIC I/O IF SD-FEC encoder TX DSP I/O IF MUX IC XI XQ YI YQ Dual I-Q Mod. Framer IC I/O IF SD-FEC Decoder (FEC) Other Rx DSP Adaptive Equalizer (AEQ) Fixed Equalizer (FEQ) 4ch A/D converter XI XQ YI YQ 100G Optical Front-End 9

10 Framer NLD G LP-DSP 20-nm CMOS Internal 4x DAC, internal framer with EFEC 70%-less power consumptions and footprint If compared with 40-nm three-chip solution I/O IF SD-FEC Encoder TX DSP 4ch D/A converter XI XQ YI YQ Dual I-Q Mod. Line estimation I/O IF SD-FEC Decoder (FEC) Other RX DSP Adaptive Equalizer (AEQ) Fixed Equalizer (FEQ) 4ch A/D converter XI XQ YI YQ 100G Optical Front-End Lower Power <20W with 20nm 10

11 Gen-2 Low Power DSP Gen-1 DSP Target Applications 2012 ~ Long Haul (LH) ~ 2,000 km p2p DWDM 2013 ~ Metro-Regional (MR) ~ 600 km ROADM Ring 2014 ~ Metro-Access (MA) ~ 600 km p2p WDM 2014 ~ Data Center Data Center ZR ~ 100 km Dark Fiber 11

12 Specifications selectable function matrix Metro Short access range (1,000 (100 Km) km) Client Items Modulation format Nyquist filter Signal bit-rate (Selectable) Chromatic dispersion compensation Net coding gain Dispersion estimation time Polarization tracking speed Frequency offset compensation Client signal (Selectable) 100GbE 100GE 7% HD-FEC E-FEC SD-FEC (LDPC) ON Specification DP-QPSK ON / OFF Gb/s (OTU4V mode) Gb/s (OTU4 mode) +/-55,000 ps/nm 11 db (SD-FEC + E-FEC) 17 msec 50 KHz +/- 5 GHz 100GbE CAUI / OTU4 OTL4.10 CD compensation (ps/nm) 55,000 Nyquist filter ON OUT4 OTU4 G-FEC OFF 20,000 OFF OFF 10,000 2,000 12

13 Lower Power by 20nm and function selection Lower Power < 20W with 20nm 13

14 Current Solutions for Coherent MSA 40nm discrete three-chip configuration 100G OTN Framer, 100G DSP, and Transmit Mux 14

15 Coherent CFP enabled by LP-DSP LP-DSP integrated the three-chip functions 70%-less power dissipations 70%-less foot print If compared with three-chip solutions 15

16 LP-DSP mounted CFP with InP Modulator THPDP1-4:OECC2014 PDP TX Output (Optical) Rx Input (Optical) InP DP-IQ Modulator Tunable Laser Modulator Drivers Integrated Receiver DAC ADC Coherent SD- FEC DSP Framer Gbps x GE /OTU4 10 Controller MDIO interface MDIO: Management Data Input/Output Photo courtesy of 16

17 Norm. output power [db] InP-based DP-IQ modulator PMF XI XQ p/2 SMF Out In YI YQ p/2 Modulator configuration Differential drive SMT I/F for RF FPC I/F for DC Bias voltage: < 10 V Vp: 1.9 V@DC, < GBaud Module size: x 6.5 mm InP DP-IQ modulator (12 x 39 x 6.5 mm) XI XQ YI YQ Push-pull driving voltage [V] Extinction characteristics

18 Tunable laser: micro ITLA Etalon Filter PD2 PD1 TEC1 TEC2 Fiber Tunable DFB Laser Array Wavelength Locker Compact tunable laser module (8 x x 6.2 mm) Micro-iTLA (20 x 35 x 6.9 mm) Compact laser module installed in OIF compliant micro-itla Use of stable DFB array-type LD Output power: 16 dbm Spectral linewidth: < 300 khz 18 Spectral ITU-T Grid PETRA Confidential

19 ICR (Integrated coherent receiver) Integrated coherent receiver (16 x 30 x 5 mm) Module configuration OIF compliant (type 2) Silica-based PLC DPOH (Dual Polarization Optical Hybrid) Hybrid integration of photodiodes via micro lens array Wide input power dynamic range with integrated VOA 4-ch PD array Signal line Micro-lens array Subcarrier Waveguides TIA Silica PLC Base Side view 19 PETRA Confidential

20 Coherent detection with ICR LO power = 13 dbm OSNR = 16 db 20 PETRA Confidential

21 Eye-diagram and consternation X Pol. X Pol. Y Pol. Y Pol. Transmitted optical waveform Real-time received constellations OSNR: 30dB (0.1nm resolution) 21

22 Real-time measured post-fec BER vs. OSNR

23 Si photonics Leverage CMOS facilities Ecosystem including ext. CMOS fab is to be established. Good mass producibility: wafer size is 8 or 12 inches Shrink size of optical devices Smaller optical circuits (R~5mm) Larger propagation loss, phase error, -5 and polarization dependence must be handled Coupling with optical fiber is challenging Can integrate active elements such as modulator and photodiode delta = 0.3%, 7.2x SM fiber SiP InP Silica PLC Passive Yes Yes Yes PBS, PR Yes Difficult Yes Modulator Yes Yes Hybrid PD Yes Yes Hybrid Laser Hybrid Yes Hybrid TO effect ~10-4 /T ~10-4 /T ~10-5 /T delta = 41.32%, x Si nanowire

24 Electronics integration with Si photonics 100G one-chip Rx Photonics: WDM filter array and Ge PD array Electronics: TIA integration by flip-chip bonding HF probe CPW CPW chip HF probe PIC wafer HF evaluation set-up 25 G x 4-ch TIAs K. Takeda, GFP 14 4l x 25G TIA output of 25 G IMDD (PRBS ) PD input: -10 dbm

25 Compact Optical Tx and Rx DSP Assist Tx Chirp Vpi Extinction ratio LD Coupling loss PBC PBS DAC LD ADC DSP Rx Phase error Loss imbalance Performance enhancement by DSP

26 Thank you 26