ECOC 2009 workshop 7-5 Sep. 20, 2009 PLC-based integrated devices for advanced modulation formats Y. Inoue NTT Photonics Labs. NTT Corporation NTT Photonics Laboratories
Hybrid integration of photonics & high speed electronics Telecom traffic keeps growing 1.4 times per year in Japan Broadband access, video service, etc. Need to improve spectral efficiency due to limited bandwidth Advanced formats are studied DQPSK, DP-QPSK, QAM Issues : Complicated and large-size photonic devices High-speed parallel electrical wirings Approach : Hybrid integration of photonics & high speed electronics Tx : Light-source, driver, modulator Rx : Local oscillator, 90-deg. Hybrid, PD, TIA TRx Tx LS Mod Ser Drv Des Rx PD TIA 90HB LO/DLI Photonics Electronics NTT Photonics Laboratories 2
Silica PLC (planar lightwave circuit) Advanced formats need lightwave functions Coupler, delay line, PBS, pol. rotator, wavelength multiplexer Silica PLCs are suitable for their hybrid-integration Pros Cons Mass producible, High reliable (optical splitter, AWG) Tunable with TO phase shifter (VOA, switch) Various passive circuits (coupler, PBS, pol. rotator, DI, MUX) Easy horizontal development Once you established PLC hybrid assembly, you can easily develop other functional devices by replacing the PLC only. Large in size compared to monolithic approach Passive function only NTT Photonics Laboratories 3
PLC-LN Hybrid-assembly Modulator NTT Photonics Laboratories 4
PLC-L PLC-LN hybrid assembly modulator Active alignment LiNbO 3 phase modulator PLC-R Light-source + Modulator + Driver NFP of LN-WG 4:3 2:1 2:1 4:3 Hybrid-integrated transmitter Bit rate (Gbps) >100 100 40 NFP of PLC DQPSK RZ p /4 40G (RZ-DQPSK) OFC2008 DQPSK p/4 HWP TE PBC TM 100G (DP-QPSK) ECOC2008 >100G (64QAM) ECOC2009 Features High-functional Compact Low-loss 2008 2009 NTT Photonics Laboratories 5
40 Gb/s RZ-DQPSK modulator PLC-L LN PLC-R PSK1 /2 PSK2 PSK1 RZ p/2 DQPSK Mod. RZ Mod. PSK2 Single side input/output by U-turn waveguide 27 GHz Module size: W18.3 L97.0 H7.8mm Insertion loss: 6 db Extinction ratio: 25 db V: 5 V NTT Photonics Laboratories 6
100 Gb/s DP-QPSK modulator TM QPSK1 HWP TE PLC LN QPSK1 HWP PLC LD TM PBS PBS QPSK2 QPSK2 HWP: Half-wavelength plate PBS: Polarization beam splitter QPSK mod. x 2 + PBS Low insertion loss: 4.8 db 100-Gb/s (25-Gbaud) operation Optical intensity [10 db/grid] 50 GHz 1584.4 1584.9 1585.4 1585.9 Wavelength [nm] H. Yamazaki et al., ECOC'08, Mo.3.C.1 NTT Photonics Laboratories 7
Binary-drive 64QAM Modulator PLC-L LN PLC-R QPSK1 VOA Input QPSK2 Output Asymmetric coupler QPSK3 Signal electrode TO phase shifter Optical intensity [10 db/grid] 20 GHz Package: 146.0 x 18.7 x 11.0 mm NTT Photonics Laboratories 8 194.06 194.08 194.1 194.12 Frequency [THz] Clear constellation w/o EQ. (BER = 7.8 x 10-4 ) Signal BW = 20 GHz : 1/3 the bit rate Insertion Loss = 5.5 db To be presented in 2.2 (Mon 16:15) by H. Yamazaki
PLC-based Receiver Front-End NTT Photonics Laboratories 9
Technology Roadmap for High-speed Receiver FE using PLC Demodulator and Balanced OE DP-QPSK receiver FE 100G DP-QPSK DPOH(PBS+90HB) DQPSK receiver FE 2ch OE converter 20mm Hybrid integration 40G DQPSK Ribbon fiber 1ch OE 2008 2009 43G DQPSK Demodulator DQPSK 2ch OE receiver FE Compact Athermal NTT Photonics Laboratories 10 2010 2011 Approach : PLC demodulator + Balanced-OE 2012
40 Gb/s DQPSK Receiver Front-End 2ch OE converter Delay Line Ribbon fiber I-ch 20mm Q-ch PLC demodulator 2-ch. balanced OE Ribbon fiber 43G DQPSK Demodulator 0 Transmittance (db). -10-20 -30-40 I-ch Q-ch 1589.8 1589.9 1590 1590.1 1590.2 Wavelength (nm) PLC demodulator Compact Fast optical phase tuning Small PDf NTT Photonics Laboratories 11 DC leads 21.5 x 34.5 x 6.7 mm 3 RF leads 2 sets of balanced-pd and TIA/AGC RF leads instead of GPPO connectors T. Furuta, ECOC 2008 P.2.13
Signal LO Dual Pol. 90-deg. Optical Hybrid (DPOH) for Digital Coherent Receiver IL < 8.5 db PBS TM TE 90 hybrid Output #1 #2... #7 #8 PLC chip Compact module 12 Transmittance [db] 0-10 -20-30 -40 TE TM Output #2 < -25 db -50 1530 1540 1550 1560 Wavelength [nm] 1570 Transmittance spectra of PBS Phase difference [degree] 100 95 90 85 TE TM < 90+/-3 deg. 80 1530 1540 1550 1560 1570 Wavelength [nm] Phase difference between I and Q channels NTT Photonics Laboratories 12 To be presented in 2.2 (Mon 17:30) by Y. Sakamaki
Summary 13 PLC-based hybrid integration is a promising approach to realize high-functional devices for advanced modulation formats Feed-through RF pins is one of the solution for high speed parallel electrical wirings. NTT Photonics Laboratories 13
14 Thank you NTT Photonics Laboratories 14