High-Speed Opto-Electronic Components for Digital and Analog RF - PowerPoint PPT Presentation

High-Speed Opto-Electronic Components for Digital and Analog RF Systems K. Y. Liou Director Laser Technology & Government Business Multiplex, Inc. kyliou@multiplexinc.com WOCC April 23, 2005 5000 Hadley Road South Plainfield, NJ 07080 USA www.multiplexinc.com

Active Opto-Electronic Component Solutions for Optical Networks Access Metro Regional Long-Haul (2-10km) (20-40 km) (60-80 km) 80+ km) Custom Design Systems 1550 Transponder 1310 Transponder Tunable EML 980 Pump Laser (EDFA) APD Receiver PIN Receiver 1550 EML (10 Gb/s) 1310 EML (10 Gb/s) 1550 EML (2.5 Gb/s) * 2.5Gb/s application extends to >640 km

Electro-absorption Modulated Laser (EML) 1E-4 1E-4 1E-4 0 km 0 km 0 km 10 Gb/s EA Modulator 1E-5 1E-5 1E-5 50km 50km 50km p-InGaAs/InP Cap Section DFB Laser 1E-6 1E-6 1E-6 85km 85km 85km Section 1E-7 1E-7 1E-7 AR BER BER 1E-8 1E-8 1E-8 HR Fe:InP 1E-9 1E-9 1E-9 Blocking 1E-10 1E-10 1E-10 n-InP Substrate Selective-Area 1E-11 1E-11 1E-11 MOCVD Grown 1E-12 1E-12 1E-12 InGaAsP MQW-SCH 1E-13 1E-13 1E-13 Grating 1E-14 1E-14 1E-14 1E-15 1E-15 1E-15 -32 -32 -32 -31 -31 -31 -30 -30 -30 -29 -29 -29 -28 -28 -28 -27 -27 -27 -26 -26 -26 -25 -25 -25 -24 -24 -24 -23 -23 -23 -22 -22 -22 <P> (dBm) <P> (dBm) • MQW DFB laser and EA modulator • Low cost integration by SAG (selective area growth) • Fiber packaging same as DFB laser • 80-km DWDM transmission • Replaces hybrid-packaged Laser-LiNbO3 modulators even for long-haul DWDM

Wavelength Tunable EML -6 10 -7 10 -8 10 -9 10 -10 10 1556 1.542 1.544 1.546 1.548 1.550 1.552 1.554 1.556 1542 Wavelength (nm.)

From MOCVD Wafer Growth to Subsystems and Fiber Transmission Test

Selective Area MOVPE Growth Increased concentration Group III Precursors > 40-50 meV( ∆λ ≈ 100 nm) Eg Enhanced • Vapor phase diffusion 40-60 µ m • Surface migration SiO 2 mask Z InP Modulator Laser (1) Indium rich (compressive strain) MQW inside slot (2) Thicker MQW layers inside the slot (Red shifted)

Micro Photo Luminescent Measurement 80 Quantum Well Number: 9 Wells Wavelegnth Offset (nm) 7 Wells Group-III Precursors 40 – 50 meV • Vapor-phase diffusion E g 60 3 Wells • Surface migration z 40 SiO 2 mask z 20 DFB MOD. Cross-Sectional Top View View During Growth 0 0 5 10 15 20 SAG Oxide Width ( µ m) • Calibration of SAG-MOCVD growth • Bandgap λ λ shift by well thickness (and alloy composition, strain) • SAG mask design for active (source, modulator, detector) and passive waveguide integration

Cross-sectional Transmission Electron Microscopy of MQW and DFB Grating Structure 56.5nm 52.2nm MQW layers 132.6nm 213.1nm 36.9nm Grating 158.7nm

10 Gb/s 85km EML Module BER Fiber Transmission Test MTX510EW SN: FZ0091 Date: 3/17/2004 Vc2 = -3.70V Cross % = 47% laser current = 100mA Pmod = 3.67dBm 1E-4 0 km 1E-5 50km 1E-6 85km 1E-7 BER 1E-8 1E-9 1E-10 1E-11 1E-12 1E-13 1E-14 1E-15 -32 -31 -30 -29 -28 -27 -26 -25 -24 -23 -22 <P> (dBm) Laser operating current 100mA, Filtered eye diagram of 85km EML modulated power 3.67dBm module

Tunable EML (DBR laser+EA modulator) 0 0 0 -6 -6 -6 -6 10 10 10 10 Relative Power (dB) Relative Power (dB) -10 -10 -10 -7 -7 -7 -7 10 10 10 10 -20 -20 -20 -8 -8 -8 -8 10 10 10 10 -30 -30 -30 -9 -9 -9 -9 10 10 10 10 -40 -40 -40 -10 -10 -10 -10 10 10 10 10 1.542 1.542 1.542 1.542 1.544 1.544 1.544 1.544 1.546 1.546 1.546 1.546 1.548 1.548 1.548 1.548 1.550 1.550 1.550 1.550 1.552 1.552 1.552 1.552 1.554 1.554 1.554 1.554 1.556 1.556 1.556 1.556 Wavelength ( µ m) Wavelength ( µ m) 1E-4 Ch_0; Back to Back Ch_4; Back to Back • Wavelength tuning Ch_9; Back to Back 1E-5 Ch_0; After 50km characteristics (12 nm Ch_4; After 50km Ch_9; After 50km 1E-6 range) BER. 1E-7 • Fiber transmission test at 1E-8 1E-9 50-GHz spaced ITU 1E-10 channels 1E-11 1E-12 1E-13 1E-14 10 Gb/s TEML -25 -24 -23 -22 -21 -20 -19 -18 -17 -16 -15 31 -1 @ 10Gb/s <P> (dBm) PRBS=2

2.5 Gb/s 640km EML Module Filtered eye diagram of 640km 2.5 Laser operating current 60mA, Gb/s EML module modulated power 0.07dBm Integrated wavelength locker for DWDM

The Multiplex Family of EMLs Gen-1 EML Gen-2 EML Gen-3 EML 7-pin with GPO 14-pin butterfly package 21-pin package Industry-standard 30GHz through pin 50GHz RF feed- configuration replaces GPO through pins Qualified to Telcordia EML driver IC inside G-S-G coplanar 50 GR-468-CORE package Ohms ports Qualified to Telcordia Integrated driver IC GR-468-CORE and wavelength locker

High-Speed EMLs Next Generation EML Products • 2.5G EML w/WLL - Current Product • 10G GPO EML w/WLL - March/2005 • 10G Tunable EML w/WLL (5nm Tuning Range) - Current Product • 10G Tunable EML w/WLL (12nm Tuning Range) - Q3/2005 • Miniature 10G Tunable EML w/WLL - Q3/2005

Introducing: Injection Locked Laser Transmitter R&D Team: Multiplex Inc, UC Berkeley, UCSD Sponsored by: DARPA RFLICS

Directly Modulated Analog Fiber Optic Links Output Input Laser Analog Analog Signal Signal Direct Modulated Link Modulation Response Increase Bandwidth Increase Efficiency Issues of Direct Mod Laser Issues of Direct Mod Laser – Low RF efficiency – Low RF efficiency – Limited bandwidth – Limited bandwidth – Nonlinear distortions – Nonlinear distortions Modulation Frequency

Monolithic Injection Locking Using Two Section DFB Laser Optical I DC I DC +I RF Circulator Polarization Controller Master Laser Slave Laser Output Conventional Optical Injection Locking: Bench Top Slave Slave • Single laser package DFB DFB • No optical isolator / circulator • Automatic polarization match Master Master and optical alignment DFB DFB • Current tuning • Environmentally robust New Monolithic Optical Injection Scheme Invented in RFLICS Program

Injection-locking by Two-section DFB Laser Locking Regime of Externally Injection-locked Laser 10 Unlocking 5 G Hz ] 0 Linewidth Enhancement Factor α Unstable f SL ) [ Locking -5 � Asymmetric Stable Locking Range -10 - ∆ f ( = f M L Unlocking -15 Stable Locking -20 -25 -40 -30 -20 -10 0 fr ) [dB] inj / P out Injection R atio (= P Negative Detuning in Monolithic Injection-locked Laser Slave Slave Master Master Section Section Section Section No isolator between Master & Slave Section ∆ f Frequency Injection Locked Frequency

Monolithic Injection Locking Using Two Section DFB Laser New Monolithic Optical Injection Scheme Invented in RFLICS Program • Single laser package Slave DFB • No optical isolator / circulator • Automatic polarization match and Master optical alignment DFB • Current tuning • Environmentally robust Fully packaged module with output Integrated master-slave laser on fiber, optical isolator, master laser submount with 25 Ω termination power monitor, TEC, RF input port for direct modulation

Monolithic Injection-locked laser in 25-GHz fiber-packaged module 20 GHz Modulation Modulation Response Applied to Slave Laser SL 73.8 mA 30 free-running (ML 0 mA) 20 Injection-locked (ML 10 mA) Injection-locked (ML 15 mA) 10 Injection-locked (ML 18.6 mA) Response (dB) 0 -10 -20 -30 -40 -50 Red – injection locked 0 5 10 15 20 25 Frequency (GHz) Blue – unlocked

Monolithic Injection Locked DFB Laser -10 -10 2nd Harmonic Distortion (dBc) 2nd Harmonic Distortion (dBc) Modulation Freq. = 9 GHz Modulation Freq. = 9 GHz -20 -20 -30 -30 20 dB 20 dB -40 -40 Locking Range Locking Range -50 -50 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 5 10 15 20 25 30 35 40 45 50 55 60 65 ML Current (mA) ML Current (mA) • Improved RF modulation linearity • Suppression of harmonic distortion • Increased spurious-free dynamic range • Enhanced modulation bandwidth Enhanced performance without increasing cost by InP-InGaAsP chip integration

The Multiplex Family of Receivers Gen-1 Receiver Gen-2 Receiver Gen-3 Receiver PIN PIN and APD versions PIN and APD versions Ultra-compact surface- Single Output Co-planar differential mount MSA package outputs First with integrated limiting amplifier Unique “Gull-Wing” Pins Small-form package (> 20GHz BW)

APD (Avalanche Photodiode) Design Bonding pad Insulator InP Center junction Guard ring Multiplication Region Charge Q-layer Layer InGaAs absorber InP N-contact AR coating Incident light

Avalanche Multiplication Electric Field Hole Current M= 8 Hole Electron Incident Light Electron Current

APD BER Measurement BER Measurement RP192DL-R2100073 31 -1 @ 10Gb/s λ =1.55 µ m; PRBS=2 1E-4 25 Deg. C; V_APD=24.14V 1E-5 75 Deg. C; V_APD=26.60V -10 Deg. C; 1E-6 V_APD=21.84V 1E-7 BER 1E-8 1E-9 1E-10 1E-11 1E-12 1E-13 1E-14 1E-15 -35 -34 -33 -32 -31 -30 -29 -28 -27 -26 -25 <P> (dBm)

High-Sensitivity RECEIVERS Next Generation10Gb Receiver Products • Ultra High Sensitivity APD Receiver: 2-3 dB better sensitivity than the current APD receiver. Sample: Q3/2005; Production Q4/2005 ( Ultra Low Noise Lens APD) • Dispersion Compensation Receivers: Optical dispersion compensation + Ultra High Sensitivity APD Receiver Demonstration: Q2/2006