EPIC: The Convergence of Electronics & Photonics K-Y Tu, Y.K. Chen, D.M. Gill, M. Rasras, S.S. Patel, A.E. White ell Laboratories, Lucent Technologies M. Grove, D.C. Carothers, A.T. Pomerene, T. Conway AE Systems L.C. Kimerling, J. Michel, M.A. eals, D.K. Sparacin Massachusetts Institute of Technology M. Lipson, A.. Apsel Cornell University C. Wong Columbia University
Spectrums of Signal to Process (example: commercial wireless) 100 MHz ands (Needs more input!) 450 MHz GSM bands M M 380.2 390.2 410.2 420.2 450.4 460.4 478.8 488.8 389.8 399.8 419.8 429.8 457.6 467.6 486 496 M M M: Mobile transmit : ase station transmit MHz GSM ands DCS 1800 PCS 1900 UMTS/FDD UMTS/TDD 900 MHz M M GSM bands 849 747 762 777 792 824 869 894 890 M 915 935 960 MHz 1900 MHz GSM/UMTS bands 1710 M 17851805 M M M 1880 1910 1930 1990 2025 2170 1850 1900 1920 1980 2110 MHz roadcasting Satellites Land mobiles Fixed wireless Amateur Radiolocation 100 300 380 500 740 960 1710 2170 MHz 470 1215 1980 2110 Groups of Spectrum
Typical Wireless Transceiver Metallic cavity filter SAW or ceramic filters Active circuits 7 x5.5 x1.3 5mmx5mmx1.2mm 2mmx3mmx0.5mm Would Would like like Q s Q s >5,000 >5,000 est est if if Q >300 >300 Would Would like like Q s Q s >2,000 >2,000 Courtesy: Clark T.-C. Nguyen Would Would like like Q s Q s >10,000 >10,000
Processing Wireless Signals Optically E to O Antenna Coax Cable Antenna O to E Optical Fiber Antenna E to O OSP* + O to E Optical Fiber Signal Analysis Reduce weight, size & power Signal Analysis Signal Analysis *Optical Signal Processing, for e.g., separating signal into individual channels Government Apps Performance critical Optics compact! Commercial Apps Need to reduce Cost critical cost of optical Optics expensive! components
Cost Reduction by Integration Electronics in standard silicon PCs, PDAs, cars, cell phones, Gameoys, DVRs, standard silicon has highest volume, ensures lowest cost No equivalent of standard silicon in optics To reduce cost of optical Integrate Optical devices built on diverse technology optics on components platforms standard silicon InP, LiNbO 3, InGaAs, SiO 2 -PLCs, MEMS, LC,
EW AS-EPIC Program Objectives To demonstrate the world s first densely integrated Application Specific Electronic Photonic Integrated Circuit (AS-EPIC) using an electronic warfare (EW) application as a demonstration vehicle. Approach Integrate the best technology and designs from AE Systems, Lucent Technologies, MIT, and AWR to realize our AS-EPIC chip. This involves combining CMOS compatible, low loss, high index contrast (HIC) waveguides and electro optic components to form optical filters, modulators, and detectors. Tasks Develop an integrated, broadband (2MHz-18GHz), RF-photonic channelizer. Create an open-architecture optical component library that is completely compatible with CMOS processes. Fab devices at AE Foundry and characterize at team test facilities 7 EW Microwave Channelizer 4.5X Increased IW IW 95X Reduction Reduction in Size Size 80X Reduction in in Weight 5X Reduction in in *Power* 100X Reduction Reduction in Cost in Cost Nickel Size EPIC RF Photonic Channelizer Chip
Why Now? FEATURE SIZE (nm) 10000 1000 100 10 1 Moore s Law Electron λ (~ 10 nm) QUANTUM REGIME 1980 1990 2000 2010 2020 Year 2004 Photon λ (~ 350-400 nm) 90 nm Technological advances in standard silicon processing makes this the right time!
Optics Integration with Silicon OPTICS in standard silicon Electronics ELECTRONICS in standard silicon Use same standard silicon processes to build optical and electronic functionality Electronic & Photonic Integrated Circuits
EPIC Channelizer Chip RF IN Optical Channellizer Filter 1 Detector TIA LASER 20 X 20 mm Chip 100 Photonic Devices 1000 Electrical Devices Modulator Multimode Interferometric Splitter Filter ank Detector TIA Optical Filter Elements Optical ends & Transitions Modulator AS-EPIC lock Diagram Modulator Mode-locked Laser Multi-mode Interferometric Splitter 300MHz to 2.2GHz RF Multimode Interferometric Splitter One Element of A Filter ank Filter n Detector/TIA Detector Optical Channelizer Slice TIA Detected Waveforms (Electrical)
Optical Waveguides Transmission Loss = 0.35 d/cm Phase I Goal: <0.5 d/cm achieved SOI waveguides achieved 0.35 d/cm transmission loss Latest waveguide short loop demonstrated State of the Art transmission loss for highly confined deposited waveguides (~4 d/cm) Standard test structure for waveguide loss
Courtesy of Armani, Spillane, Kippenberg, Vahala
Filter Layout Fully tunable 4 th order pole-zero filter Phase shifter In Κ=0.5 R 1 R 2 Κ=0.5 R 3 R 4 Tunable MZ coupler κ 1, φ 1 κ 2, φ 2 β-φ tot Through In φ tot -β Cross κ 1, φ 1 κ 2, φ 2 Can dynamically move the zeros & poles of the 4th order filter providing wide range of passband tunability
Transmittance (d) Flexible Channel Tuning 0-10 -20-30 f 0-2.5 GHz f 0 f 0+2.5 GHz Single design can work for all channels! -40 193.408 193.412 193.416 193.420 Frequency (THz) RF In Filter 1 Detector TIA RF Out CW LASER Modulator Silicon Chip Multi-mode Interferometric Splitter Filter n Detector TIA RF Out
(andwidth) x (Quantum efficiency) 80 70 60 50 40 30 20 10 0 Size : 5µm 20µm Q.E: 90% transit time limit Ge-on-Si Photodetector Integration Waveguide-Integrated, EPIC Photodetector RC time limit d=0.5um d=1.0um d=1.5um d=2.0um 10 2 10 3 10 4 Detector Size µm( 2 ) Discrete, free-space Photodetectors Ge Photodetector Wavelength W (nm) Responsivity (A/W) Size (um) Speed (Gb/s) Waveguide - Detector Coupling Efficiency
Micro-ring Modulator Width = 450nm Gap = 200nm Diameter = 12_m Lowest power consumption reported to date. - Less than 0.3V and µa current needed for complete modulation in DC. - In AC, 3.3Vpp and 1mA current were used. Expected theoretical bandwidth 1.5 Gbit/s using RZ pattern limit >10Gb/s!
RF Performance of Channelizer Photonic LO f 0 + 2.5GHz f 0 Up-converted signal Tuned to f 0 +3.1GHz center NF = 68d IIP3 = 26dm SFDR = 88 d*hz 2/3 etter preamp, higher LO, lower optical loss will further improve system NF and SFDR
AS-EPIC Summary Devices Optical filter: design, fabrication and test the most sophisticated tunable optical filter with CMOS processing the first optically-lossless CMOS thermo-optic switching (TOS) Si waveguide: design, fabrication and test SOI (0.35d/cm) and deposited silicon ( 4d/cm) Ge detector: design, fabrication and test W=2.5GHz@1500nm, R>0.8A/W Si Modulator: design, fabrication and test =6 Gbit/sec, ER=15 d, L=10 µm, 3mW System SFDR: measured 88 d*hz 2/3 in surrogate system Channel Rejection: measured >28.6 d rejection ratio