《光通信技术》课件：Lecture1 Introductiondefinition.pptVIP

Department of Optical Engineering 2013 Fiber-Optic Communications TechnologyInstructor: X. Wu Department of Optical Engineering, 2008 Course OutlineOverview of Photonic CommunicationsOptical Fiber: Waveguiding, Propagation Modes - Single Mode Fiber - Fiber Materials Fabrication ProceduresSignal Degradation in Optical FibersPhotonic Sources Transmitters: LED Laser Diodes - Single Mode Lasers, Modulation NoiseLaser-Fiber Connections (Power Launching Coupling)PhotodetectorsDigital Photonic Receivers Digital Transmission systems WDM Photonic Networks Department of Optical Engineering, 2008 Lab Computer SimulationsLab sessions - Fiber Attenuation Measurement - Dispersion Measurement - Spectral Attenuation MeasurementsComputer Simulations using Photonic software - Over ten design exercises using Optiwave - Cover most linear and nonlinear phenomena - Excellent system design practice Department of Optical Engineering, 2008 Introduction/definitionTelecommunicationsWhat is it? Exchange of information over a distanceNet configurations: 1.point-to-point 2.networks: a) Mesh topology b) star topology c) ring topology d) bus topology Department of Optical Engineering, 2008 Optoelectronic Technology in Our Life Everyday Department of Optical Engineering, 2008 IntroductionWhy go digital? Advantage: less misinterpretationDisadvantage: requires more channel capacityMajor demandHigher capacityLower cost Department of Optical Engineering, 2008 Shannon-Hartley theoremCapacity v.s. bandwidth (1948)Capacity (bits/sec)=BW(Hz)xlog2(1+SNR)Channel bandwidth v.s. Carrier-signal freq Channel bandwidth (Hz) ? 0.1XCarrier-signal freq. (Hz) Department of Optical Engineering, 2008 From copper wire to optical fiberCarrier-signal freq. limit:Copper wire 1MHzCoaxial cable 100 MHzRadio freq. 500