Question

The largest number of modes of
propagation of light rays are possible for​

Answer 1

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Light propagates as an electromagnetic wave inside the optical fiber. This wave can propagate either in one mode, i.e., “single-mode fiber” or in multiple simultaneous modes, i.e., multimode fiber (Figure 4a). The number of modes that may propagate at a given wavelength depends on the diameter of the optical fiber core. The overall diameter of an optical fiber is made up of the diameter of the optical fiber core, the width of annular cladding, and the protective outer coating (Figure 4b). Optical fibers with a smaller core allow only a single mode; larger fibers allow multiple modes. When the core diameter is around , the optical fiber may carry only the fundamental LP01 mode (Figure 4c, left); hence, it is called “single-mode fiber”. If the core diameter is larger, say between and , the optical fiber allows more than one mode of the light wave to propagate (e.g., up to the LP21 mode, as shown in Figure 4c, right); hence, it is called “multimode fiber”. A fiber-optic sensor can be constructed from either a single-mode or a multimode optical fiber depending on application. A single-mode optical fiber with a smaller core is much more sensitive than a multimode optical fiber; this may be a desirable feature in damage detection based on strain measurements. A multimode fiber changes its properties more readily in response to microbends and other disturbances, hence it has been preferred in other damage detection sensors.

Answer 2

Answer:

Radio Wave Propagation

Line of sight (LOS) propagation.

Ground wave propagation.

Sky wave propagation.