I’m looking for the angle of incidence of the HD-DVD optical system.
I know the formula to calculate the numeric aperture:
NA = n * sin(u)
n is the refractive index and u the angle of incidence. We all know, that the NA of HD-DVD is 0.65. The refractive index is 1.62. So I could change the equation to
NA/n = sin(u)
0.65/1.62 = sin(u)
But my mathematics lessons are really to long ago, so I don’t know how to depatch the equation. By using a loop to solve the problem by testing, I get different results for u, where the NA is 0.65 and the refractive index is 1.62.
Can anyone help me?