question_answer

What should be the maximum acceptance angle at the aircore interface of an optical fibre if \[{{n}_{1}}\]and \[{{n}_{2}}\] are the refractive indices of the core and the cladding, respectively?

A) \[{{\sin }^{-1}}({{n}_{2}}/{{n}_{1}})\]

B) \[{{\sin }^{-1}}\sqrt{n_{1}^{2}-n_{2}^{2}}\]

C) \[\left[ {{\tan }^{-1}}\frac{{{n}_{2}}}{{{n}_{1}}} \right]\]

D) \[\left[ {{\tan }^{-1}}\frac{{{n}_{1}}}{{{n}_{2}}} \right]\]