Optical Communication et4-013 B1 Optical Communication Systems Opto-Electronic Devices Group Delft University of Technology Opto-Electronic Devices Group Delft University of Technology Meint Smit Xaveer Leijtens Siang Oei Meint Smit Xaveer Leijtens Siang Oei Course et4-013

Optical Communication et4-013 B2 Contents  Introduction  Fibre transmission properties  Light sources (laser, LED)  Light detectors  Optical receivers  Fibre systems  Introduction  Fibre transmission properties  Light sources (laser, LED)  Light detectors  Optical receivers  Fibre systems

Optical Communication et4-013 B3 Fibre performance z=0z=L Dispersion z=0z=L Attenuation

Optical Communication et4-013 B4 Fibre attenuation (SiO 2 ) Wavelength (  m) Attenuation (dB/km) dB/km Rayleigh scattering IR band edge OH - -peak UV absorption

Optical Communication et4-013 B5 Bandwidth and Bit rate t TT FWHM dBo fofo fefe dBe I det = R·P opt (:)  P el Rule-of-thumb:  

Optical Communication et4-013 B6 Types of dispersion  Intermodal dispersiononly for MMF  Material DispersionChromatic  Waveguide DispersionDispersion  Polarisation Mode Dispersion (PMD)  Intermodal dispersiononly for MMF  Material DispersionChromatic  Waveguide DispersionDispersion  Polarisation Mode Dispersion (PMD) } {

Optical Communication et4-013 B7 z=0 Chromatic dispersion TT z=L

Optical Communication et4-013 B8 Phase velocity (mode) z

Optical Communication et4-013 B9 Group velocity (pulse) z

Optical Communication et4-013 B10 Material Dispersion (1)

Optical Communication et4-013 B11 Material Dispersion (2)

Optical Communication et4-013 B12 Material Dispersion (3) Material Dispersion SiO

Optical Communication et4-013 B13 Standard Single-Mode Fibre

Optical Communication et4-013 B14 Fiber classification (1) Core diameter  m Cladding125 (500)  m 2 nd coating  m NA Attenuation1 - 4 dB/km BL-product MHz.km ApplicationShort distance, low cost limited bandwidth Core diameter  m Cladding125 (500)  m 2 nd coating  m NA Attenuation1 - 4 dB/km BL-product MHz.km ApplicationShort distance, low cost limited bandwidth MM-SI: Multi Mode - Step Index fiber

Optical Communication et4-013 B15 Fiber classification (2) Core diameter50  m standard Cladding125  m 2 nd coating  m NA Attenuation1 dB/km (1300 nm) BL-product 150 MHz.km - 2 GHz.km ApplicationMedium distance communication LED/Laser sources Core diameter50  m standard Cladding125  m 2 nd coating  m NA Attenuation1 dB/km (1300 nm) BL-product 150 MHz.km - 2 GHz.km ApplicationMedium distance communication LED/Laser sources MM-GI: Multi Mode - Graded Index fiber

Optical Communication et4-013 B16 Fiber classification (3) Core diameter3-10  m Cladding  m 2 nd coating  m NA~0.1 (not used) - dB/km BL-product >> 500 MHz.km ApplicationLong distance communication Lasers, standard fiber Core diameter3-10  m Cladding  m 2 nd coating  m NA~0.1 (not used) - dB/km BL-product >> 500 MHz.km ApplicationLong distance communication Lasers, standard fiber SM-SI: Single Mode - Step Index fiber

Optical Communication et4-013 B17 Waveguide dispersion n 1 ( ) n 2 ( )

Optical Communication et4-013 B18 Dispersion shifted fibre

Optical Communication et4-013 B19 Dispersion Mechanisms Intermodal multimode fiber! Intramodal / Chromatic material n waveguide

Optical Communication et4-013 B20 Optimal Pulse Width Gaussian pulse:

Optical Communication et4-013 B21 Soliton Transmission t    E tot =2   T FWHM=1.76T n(E)n(E) Pulse Compression

Optical Communication et4-013 B22 Erbium-Doped Fiber Amplifier (EDFA) PUMP LASER 0.98  m or 1.48  m Er-doped fiber MUXFILTER