Fibers for Optical Communications

Abstract

Low‐loss optical fibers based on silica now have a transmission loss value approaching the theoretical limit, and thus attention has turned to other materials. Fibers for optical communications are reviewed in general, and the methods of loss reduction in silica‐based fibers are discussed. Advanced materials and new processing technologies are described for active fibers, in which the light is intentionally modified as it propagates along the fiber, as well as for ultra‐low‐loss passive fibers.

Glass and bioglass nanopowders by flame synthesis

“…For thousands of years they have been broadly used for their intriguing properties 1,2 including elasticity, 3 transparency, 4 and chemical resistance, 5 and today they are workhorses in data transmission. [6][7][8] In medicine, certain glass compositions (SiO 2 -CaO-P 2 O 5 -Na 2 O) were even found to form tight bonds to living human bone and are applied in a variety of bone grafts for bone repair and regeneration of defects arising from trauma, tumour and osteoporosis. [9][10][11][12] Traditionally, oxidebased glasses have been derived by melting of the corresponding oxides at elevated temperatures 13 and result in dense or lowporosity texture materials.…”

Coherent Perfect Absorber Based on Antisymmetric Metasurface With Gain Material

“…With the development of optical fiber communication [1], the disadvantages of electronic devices such as power consumption and low efficiency are gradually exposed, resulting in the phenomenon of electronic bottleneck in communication network [2]. In order to solve this problem, all-optical communication technology [3] has attracted a lot of attentions recently.…”

Generation of Terahertz Radiation by Optical Excitation of Aligned Carbon Nanotubes

“…Another way of generating THz pulses involves excitation of a transient photocurrent by an ultrafast optical pulse. The photocurrent can be driven by an applied bias voltage such as in a photoconductive switch, − by intrinsic electric fields at semiconductor surfaces, or by differences in electron and hole mobilities (photo-Dember effect), resulting in transient charge separation upon excitation of a semiconductor surface. , Recently, generation of THz pulses in thermoelectric materials such as BiSnTe and BiTeSe by the fast diffusion of free majority carriers as a result of an ultrafast laser-induced temperature gradient (Seebeck effect) has also been observed . THz emission with efficiencies surpassing that of bulk semiconductors has been reported in a variety of nanowires and nanorods. − In these experiments, dense, vertically aligned nanowire or nanorod arrays on growth substrates were excited by ultrafast optical pulses at off-normal incidence.…”