Numerical Aperture.

[lord loh.]

I am being introduced to fibre optics in the class and all text books I feffer to derrive Numerical Aperture by applying pythogaras formula on a triangle having refractive indices as it's sides.

NA= √{n1²+n2²} (Square root)

How can the refractive indices be proved to be proportional to the dimentions of the triangle...

Moreover, does the numerical aperture depend on the dimentions of the cable?

 

[akg]

Moreover, does the numerical aperture depend on the dimentions of the cable?

No.. NA denotes the maximum conical angle, from which a light ray could enter the fiber, to have total internal reflection .

 

[akg]

I am being introduced to fibre optics in the class and all text books I feffer to derrive Numerical Aperture by applying pythogaras formula on a triangle having refractive indices as it's sides.

NA= √{n1²+n2²} (Square root)

How can the refractive indices be proved to be proportional to the dimentions of the triangle...

Moreover, does the numerical aperture depend on the dimentions of the cable?

one more thing .. the refractive indices and trignometry get releted because , when a light ray enters a medium with different 'n' .. the light bends WRT 'normal' and the angle subtended is in relation with the 'n' .
got it..??