Learning Outcomes
1. Understanding light guidance in planar waveguides and optical fibers and feels confidence with mode calculations in such guides.
2. Detailed analysis of dispersion mechanisms and pulse propagation in single-mode fibers.
3. General understanding of semiconductor optical sources technology, with emphasis on laser-diodes.
4. Photodiodes and optical receiver basics, including noise sources and fundamental limitations.
5. IM/DD (OOK) systems: system-level performance, BER, SNR, etc. Multiplexing techniques.
Course Content (Syllabus)
Evolution of optical communication systems overview.
Optical waveguides and optical fibers: characteristics, ray theory and wave theory, guided modes, mode classification. Special types of fibers. Slab waveguides and planar optical waveguides.
Transmission in optical fibers: Attenuation mechanisms. Classification of dispersion mechanisms, material dispersion and waveguide dispersion. Transmission equation in single-mode fibers. Transmission of Gaussian pulses when subjected to GVD & TOD, transmission of arbitrary shape pulses, effect of source finite spectral width. Limitation in maximum bit-rate due to dispersion.
Light sources: Laser basic principles, light emission in semiconductors, laser diodes (LD), types of LD (Fabry-Perot, Edge Emitting, VCSEL), operation characteristics, modulation. Light Emitting Diodes (LED). Coupling with fibers.
Optical detectors: PIN photodiodes and avalanche photodiodes.
Direct detection optical receiver: noise sources (thermal, quantum and dark current noise), quantum limit, signal-to-noise ration (SNR), typical receivers, receiver sensitivity, factors that restrict receiver sensitivity.
Optical communication systems: Intensity Modulation / Direct Detection (IM/DD) systems, basic architectures, design restrictions, multiplexing techniques (Optical Time Division Multiplexing OTDM, Wavelength Division Multiplexing WDM). Coherent optical communication systems (BPSK, QPSK).
Keywords
optical fibers, transmission of optical signals, laser, laser diodes, photodiodes, optical receivers, optical communication systems