PHOTONIC COMPONENTS AND DEVICES A
Learning outcomes of the course unit
The objective of the course is to give an understanding of fiber optic technology and its related devices.
Course contents summary
Optical fiber. Numerical aperture. V-number. Fractional refractive index difference. Step-index fiber. TE, TM, EH e HE guided modes. Weakly guiding fiber. LP guided modes. Power confinement factor and its dependence on V-number. Gaussian approximation: spot size and mode field diameter. Graded index and matched cladding fibers.
Fiber trasmissive properties: attenuation. Intrinsic and extrinsic attenuation causes. Rayleigh scattering. Macro and micro-bending losses. Ultra violet and infra-red absorption. Data sheets of commercial fiber types.
Fiber trasmissive properties: dispersione in fibra. Intermodal and Intramodal dispersion. Cromatic Dispersion. Dispersion Shifted Fibers (DSFs), Non-Zero Dispersion Shifted Fibers (NZDSFs), Dispersion Compensating Fibers (DCFs). Example of a DCF design.
Plastic optical fibers: material, attenuation, core and del cladding diamaters.
Optical amplification principles. Population rate equations. Four, three and two levels systems. Propagation rate equations. Absorption and gain coefficient.
Rare earth doped fiber amplifies. Design, schemes, forward and backward pumping, gain, noise figure. Evolution of signals, pumps and ASE powers along the fiber.
C, L, and S band optical amplification. Silicate, tellurite and florurate fibers. Fiber lasers.
Light emitting diode (LED) e Laser. Designs and physical operation principles.
Single longitudinal mode lasers. DFB e DBR. Tunable lasers..
Vertical Cavity Surface Emitting Lasers (VCSELs) Performances and advantages.
Photodiodes. PIN, Avalanches photodiodes. Noise sources.
Passive Components. Couplers/splitters. Wavelength Division Multiplexers and Demultiplexers (WDM MUXs/DEMUXs). Isolators, Circulators and Attenuators.
B. E. A. Saleh, M. C. Teich, "Fundamental of Photonics", Wiley Interscience, 1991.
D.K. Mynbaev, L.L. Scheiner, "Fiber-Optic Communications Technology“, Prentice Hall, 2001.
J. A. Buck, “Fundamentals of Optical Fibers”, John Wiley & Sons, 1995.
J.M. Senior, “Optical Fiber Communications”, Prentice Hall International Series in Optoelectronics, 1992.