Q1. Numerical Aperture and Acceptance angle of an Optical Fiber. (a) A light-emitting diode (LED) shines on a cleaved facet of an optical fiber as shown in the Figure 1 below. The refractive indices of the core and cladding are n1 and n2 respectively and the refractive index of air is 1. Show that the relation between the numerical aperture (NA) and the acceptance angle of an optical fiber is given by NA = sin?a = ?(n1Ā² - n2Ā²) Fig. 1: Acceptance angle of an optical fiber. (b) Determine the numerical aperture and the acceptance angle of an optical fiber if the refractive index of the core is n1=1.46 and the cladding is stripped out (replaced with air n2 = 1). (c) How does this change, when a glass cladding of refractive index n2 = 1.40, is added?
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We know that the numerical aperture (NA) is defined as: NA = ā(nāĀ² - nāĀ²) where nā is the refractive index of the core and nā is the refractive index of the cladding. Show moreā¦
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