Syllabus Fiber Optic Communication - (404190) Credit Examination Scheme : 03 In Sem (Theory) : 30 Marks End Sem (Theory) : 70 Marks Unit I Optical Fibers for Telecommunication Fundamentals of Optical Communication : EM spectrum - Optical Spectral bands, Shannon channel capacity, power units (watts, dB & dBm), Block diagram of optical fiber communications link, advantages of optical fibers. Optical Fiber Waveguides : Introduction, Total internal reflection, acceptance angle, numerical aperture, fiber types, mode theory for circular waveguides : overview of modes & key modal concepts (V number, number of modes, power in clad), single mode fibers, cutoff wavelength. Transmission characteristics of optical fibers : attenuation - material absorption, scattering losses, fiber bend loss, loss due to fiber misalignment, splices and connectors; signal distortion - intermodal delay, intramodal dispersion or chromatic dispersion, modal delay, bit rate-distance product, plot of material & waveguide dispersions for standard single mode, dispersion shifted and dispersion flattened fibers; optical fibers for 5G networks, comparison. (Chapter - 1) Unit II Optical Sources Optical Sources : Introduction, wavelength and material consideration (direct & indirect bandgap semiconductors); requirements from optical sources for telecommunication. LED : principle of working, quantum efficiency, optical output power characteristics, spectral width, effect of temperature on characteristics, modulation bandwidth, analog modulation, digital modulation, LED analog transmitter; Semiconductor Laser Diodes : absorption, spontaneous emission, stimulated emission, concept of population inversion and optical feedback, output power characteristics of LASER; Bias point and amplitude modulation range for analog applications of LEDs & laser diodes, comparison of LEDs & Lasers. (Chapter - 2) Unit III Photodetectors Introduction, requirements from optical detectors, material considerations, types : p-n, pin, Avalanche photodiode, photo transistor, principle of working, quantum efficiency, responsivity, long cutoff wavelength, detector response time, comparison of photodetectors, thermal noise, dark current noise, quantum noise and receiver sensitivity, bit error rate. (Chapter - 3) Unit IV Fiber Optic Link Design & WDM Systems Point to point optical link : Choice of components, system design considerations, optical power budget, rise time budget, bit rate for RZ and NRZ pulse format. Optical system design and performance analysis using software tools. WDM Concepts & Components : Overview of WDM, WDM components : 2 x 2 fiber coupler, isolator, circulator, basics of fiber grating filters, optical add/drop multiplexer, architecture of optical amplifiers (SOA, EDFA & FRA), Noise figure, OSNR & system impact of ASE. (Chapter - 4) Unit V Optical Networks Optical Network concepts : fundamentals, network terminology, desirable properties, elements of an optical network, optical network topology types, advantages of optical network. Overview of Optical Networks : FDDI, SONET/SDH, FTTX, FTTP, FTTH, PON, GPON, Long haul, Metro, Access, Submarine optical networks, role of fiber optic network in the 5G networks. Current technology trends, standards and challenges. (Chapter - 5) Unit VI Optical Fiber Measurements Overview of Measurement Standards for fiber optics : Test Equipments for field work : Test support lasers, visual fault indicator, optical power meter, Optical Time Domain Reflectometry (OTDR), optical spectrum analyzer (OSA), BER test equipment Measurements : measurement of : optical power, numerical aperture of fiber, fiber attenuation (cutback method, insertion loss method, OTDR), macrobending loss, fiber dispersion. System performance evaluation : Eye Diagram Test, study of OTDR. (Chapter - 6)
