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Fiber optics - temporal broadening by a multimode fiber.

How significant is the broadening of a nsec pulse laser in the optical fibers? Their fiber was quartz, 2.5 m long, 600 um in diameter, with numerical aperture in air of 0.22. Let's assume you sent an idealized pulse of 337 nm light (from the N2 laser) with zero temporal width into the fiber. Calculate the minimum and maximum flight times using ray approximations and thereby report the broadening due to the fiber geometry alone. Is this significant for nsec pulses?

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Aperture a = 0.22 in air means that the angle A between the axis of the fiber and the ray most inclined from the axis IN AIR has sin A = a

The precise value of the index of refraction of quartz at wavelength 337 nm, should be found in your textbook. I shall take it n = 1.5 for the example here, but if you find a more precise value ...

Solution Summary

The solution explains the significance of broadening of a nsec pulse laser and what it implies for the pulses.

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