Comparison of Electrooptic and Electroabsorption Modulators

All three types of electrooptic modulators compete with electroabsorption modulators (EAM), which have now been demonstrated in the laboratory at speeds as high as 40 GHz (Ouagazzaden, 2001). An EAM works on the principle of the Franz-Keldysh effect, which is the observed lengthening in wavelength of the optical absorption edge ofa semiconductor with the application of an electric field (Noda, 1986 Reinhart, 1976 Stillman. 1976 Dutta, 1984 Noda, 1985). In multiquantum well structures this is...

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With small amounts of phosphate, sulfate, carbonate, nitrate, and titanate anions. Data for sulfate and phosphate anions were discussed in some detail. The authors concluded that sulfates and phosphates had a drastic impact on optical transparency in the near IR, and would have to be kept well below the 1 ppm level were transmission-quality fiber ever to be obtained. As noted above, the loss levels acceptable for active fiber devices are typically much higher than could be tolerated in...

System Requirements and Digital Performance

The introduction of wavelength-multiplexedsystems to enhance data-carrying capacity of the installed fiber base has significantly increased the deployment of lithium niobate external modulators. Modulators have become a critical component in the majority of today's long-haul terrestrial and submarine optical networks. Intensity modulation or on-off keying (OOK) is the predominant technique used for telecommunications transmission in optical fiber. An external modulator is switched to define the...

Design Considera Tions

Several factors must be considered in the design of polymeric MZ waveguide modulators for photonic applications. First, single-mode operation is required and can be achieved by controlling the thickness of the guiding layer. The thickness of the guiding layer is inversely proportional to the refractive index difference between the guiding layer and the cladding layers. Second, a low half-wave voltage of the modulator is required for high-speed operation. This can be achieved with a high...

Applications Of Perfluorinated Plastic Fiber

The raison d' tre for PFBVE GI-POF is to qualitatively simplify field installation of high-speed data links, especially in the gigabit-per-second regime. In comparison to silica-based optical fibers, GI-POF eliminates the need for trained installers and specialized cleaving and polishing tools. In comparison to high-speed unshielded twisted-pair UTP copper links, GI-POF simplifies the cable pulling and termination aspects of the installation process. As with all optical media, GI-POF also...

Antimony Silica

In 1997, one of us Ellison found that erbium in antimony silicate glass Sb Si exhibited promising 1530 nm spectroscopy, appearing to be at least comparable to well-optimized tellurite glasses. A major effort was undertaken to convert compositions in this system into low-loss optical fibers for use in amplifiers and lasers. Antimony silicates make high-quality, low-loss fiber and can accommodate high levels of rare earth elements without significant clustering, but have lower refractive than...

Sband Amplification

Tm3 Optical Transitions

The S-band represents a wavelength range immediately to the blue side of the low-loss window supported by EDFAs. Once the available bandwidth covered by C- and L-band EDFA systems is utilized this window is recognized as being the most likely band for expansion. Whereas gain-shifted erbium-doped fiber amplifiers are being studied for the longer wavelengths 1 570-1620 nm , thulium-doped fiber amplifiers are among the technologies under consideration for amplification in the shorter wavelength...

Raman Gain Coefficient In A Fiber

The Raman process may also be treated with a classical electromagnetic description. In single-mode optical fibers, the growth of stimulated Raman scattered signal intensity is proportional to the product of the pump and signal intensities and the gain coefficient, yr, such that where Is and lp are the intensities of the Stokes-shifted and pump waves, respectively. In general, the intensities of the pump and signal have radial, temporal, and frequency dependencies. In order to generate...