Leuthold, JuergBrès, Camille-Sophie2015-06-222015-06-222015-06-22201510.1007/978-3-319-14992-9_8https://infoscience.epfl.ch/handle/20.500.14299/115282Pulse shaping gives communications engineers another degree of freedom in designing a link. It holds promise to allow extending transmission reach, achieve optical multiplexing at highest spectral efficiency or to limit nonlinear distortions. A variety of pulse shapes—rectangular, sinc, raised cosine to cite just a few—have been investigated but the important question is how optical transmitters can generate such pulses at the necessary speed. Should the transmitter be realized in the digital domain, the all-optical domain or can it be implemented as a hybrid? In this chapter, the fundamentals for pulse shaping in transmitters and receivers are reviewed. A particular emphasis is on orthogonal frequency division multiplexing (OFDM) where the system’s data are encoded onto subcarriers with a rectangularly shaped impulse response, and Nyquist pulse shaping where the symbols are carried by Nyquist pulses. Electronic, digital and optical processors are described and recent experimental demonstrations are reported.Optical pulse shapingspectral efficiencyoptical communicationtext::book/monograph::book part or chapter