- #1
Berdi
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Homework Statement
"figure 3" (below) shows an optical fibre bent in a curve. The diameter of the fibre is 4mm. If light is not to escape, calculate the smallest radius of R of the curve round which the fibre can be bent. Assume that the fibre is surrounded by air (refractive index 1) and that the refractive index of glass is 1.5"
Homework Equations
n1
___ = SinC (critical angle)
n2
The Attempt at a Solution
Well, I've got c, the critical angle -
1
__ = 0.666... sin-1(o.666) = 41.81
1.5
But, I can seem to make a triangle with enough information to get R. I've tried splitting it up, but either get not enough information to do sine or cosine rules, or a non right angle triangle. Maybe I'm just missing something?