ced losses of optical fibers. Reprinted from Fig. 6.1-15 Dispersion VS wavelength for single-mode fiber. Ref. [15], p. 1.33, courtesy of McGraw-Hill. Reprinted from Ref. [15], p. 1.38, courtesy of McGraw-Hill. Optical fiber, cable and connectors CHAPTER 6.1 Dispersion nonshifted Single mode fiber for 1310 nm use Dispersion shifted Single mode fiber for 1550 nm use Dispersion-flattened Single-mode fiber 0.001 Flaw depth, um Fig. 6.1-17 Failure stress VS flaw size. Reprinted from Ref. [15], p. 1.40, courtesy of McGraw-Hill. Wavelength, nm affect the dispersion properties of the fiber is shown in Fig. 6.1-16 Spectral disposition for various single-mode Fig. 6.1-16. fiber profiles. Reprinted from Ref. [15], p. 1.38, courtesy of Intermodal dispersion arises from the different travel McGraw-Hill. times for the different modes in the fiber. For modal dispersion the units are nsec/km and Dmod is defined as follows [2]: Waveguide dispersion is due to the different prop- agation characteristics of the light in the core and Dmod = tmax - tmin (6.1.33) cladding. Keep in mind that a large portion of the light (30-40%) travels in the cladding for the LP01 where and tmin are the propagation times for the mode around the cutoff frequency for the next higher modes traveling the longest and shortest distances, order mode. The waveguide dispersion can be ap- respectively. Using the group index N1 [3], proximated, using the normalized propagation constant b, as (6.1.34) (6.1.32) where the term k (dn1/dk is the material dispersion for a plane wave traveling in the core region; we can approximately write the modal dispersion in a step-index The total chromatic dispersion as well as its constitu- fiber as follows [2]: ents are plotted in Fig. 6.1-15. As shown in Fig. 6.1-2, an optical fiber can have many different refractive (6.1.35) index profiles. How the refractive index profile can Table 6.1-5 Physical properties of materials Property Silica glass Copper Aluminium Steel Chemical sign Specific gravity (g/cm³) Tensile strength (kg/mm