Determine the numerical aperture of a single clad optical fiber, given that the core has an index of refraction of 1.62 and the clad  has an index of refraction of 1.52.  When immersed in air, what is its maximum acceptance angle?  What would happen to a ray incident at 45^o?

Problem 2:

Given a fused silica fiber with an attenuation of 0.2 dB/km, how far can a signal travel in the fiber before the power level drops to 1/2? 

Problem 3:

Given a step-index fiber with core diameter 50 mm, n_core = 1.5 and n_cladding = 1.482, determine the number of modes N_modes that propagate in the fiber when it is illuminated by an LED emitting at a central wavelength of 0.85 mm.

Problem 4:

In a step-index fiber in the ray approximation the ray propagating along the axis of the fiber has the shortest route, while the ray incident at the critical angle has the longest route.  Determine the difference in travel time (in ns/km) for the modes defined by those two rays for a fiber with n_core = 1.5 and n_cladding = 1.485.

Problem 5: