Exercise 3 We want to couple the energy of an argon-ion laser beam of wavelength λ = 488 nm into a fiber optic cable. Re

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Exercise 3 We want to couple the energy of an argon-ion laser beam of wavelength λ = 488 nm into a fiber optic cable. Refractive indices of the fiber optic cable are 1.62 for the core and 1.50 for the cladding. The beam of the laser has a cross sectional area of 10 mm² with negligible divergence and the entire beam has to be coupled into a diameter of 50 μm (fiber core). A lens is used to couple the laser beam into the fiber. a. Calculate the acceptance angle of the fiber b. What should the focal length of the lens be to couple the beam into such a small fiber core section (take Ds=0.7 Dc)?