Semiconducting Fiber for Photonics

With the enormous demand for high-speed, long-distance, and low-cost communicating networks, glass optical fibers have been extensively revolutionized in terms of elaboration techniques and performances, in particular the low loss of the transmitted signal. Aiming to upgrade its functionality and as a result widening its photonic applications, fundamental ameliorations have been performed on optical fibers by doping the glassy optical fiber with single or compound semiconductors. The pairing between the unique properties of semiconductors, in particular the simple processing techniques, the high refractive index, the strong light generation, and the high optical electrical conversion power with the properties of the glass optical fibers such as flexibility and long-length processing without alternating its physical properties, is promoted by the elaboration of the glass-cladding semiconductor-core optical fibers. In this context, this chapter reviews in its first part the different elaboration techniques focusing on their main benefits and drawbacks as well as the recent upgrades enabling the deposition of a new wide range of semiconductors. The second part of the chapter reports on the recent advances in semiconducting fibers used in photonic applications. Four main applications have been described: photonic waveguiding of all-optical signal processing and frequency generation, light emission, lasers, photodiode and photodetection, optical amplification, and other applications including biological and electronic sensing.