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b)
20 a)

b)

0000PHT110121801 B

Module-V
Explain construction and working of Ruby laser.
Describe the recording of hologram
Define numerical aperture of an optical fibre. With a neat diagram derive an
expression for numerical aperture of a step index fibre.
The sum of refractive indices of core and cladding is 2.9 and difference is

0.03. Determine numerical aperture and acceptance angle of optical fibre.

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