Optical glass fibers single mode

Figure 7.9 Refractive index profiles of three common types of optical glass fiber multimode step index, multimode graded index, and single mode.

The telecommunication industry requires optical glass fibers with very high strength (>1 GPa) over very long lengths (>1 km). For example, the True Wave single mode fiber of Lucent Technologies is routinely subjected to a proof stress of 0.7 GPa (see below) while the Weibull modulus is claimed to be 147 (Kummer,... 

Fig. 13. Preparation of single-mode fluoride glass optical fibers by the jacketing technique (reproduced with permission from Annales Chim. 20 (1995) 261, Gauthier-Villars, Paris).

Single mode glass fiber is widely used in the trunk area of the telecommunication system and the optical fiber system is expected to extend to the subscriber area and the network in building, offices, and homes. However, use of the single mode glass fiber system in short distance network is not necessarily suitable because it requires the precise handling and connection due to the small core size (5-10 [im) and thus it would be expensive in broadband residential area network, ATM-LAN, interconnection, etc. In contrast, polymer optical fiber (POP) which has more than 500 jim of core is promising candidate to solve such problems. 

Takeuchi Y., Mitachi S., and Nagase R., "High-Strength Glass-Ceramic Ferrule for SC-Type Single-Mode Optical Fiber Connector," IEEE Photonics Techn. Lett., 9, 1502-04 (1997). 

Unlike the previous example, a microlens etched by a dry technique on quartz glass is shown in this section. In optical communications, single mode fibers are preferred because of the absence of mode dispersion and mode noise. In order to explore a microlens whose working wavelength lies in the infrared (IR) frequency band (e.g., 1300 nm), Eisner et al. presented silicon microlenses for IR fabricated by reactive ion etching (RIE) [9]. 

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