v 8.14

α = \frac{1}{2} (α_{L} - α_{R}) = \frac{ω d}{2 c} (n_{L} - n_{R}) = \frac{π d}{λ_{0}} (n_{L} - n_{R})

${\alpha = \frac{1}{2} (\alpha_L-\alpha_R )= \frac{\omega d}{2c} (n_L-n_R )= \frac{\pi d}{\lambda_0} (n_L-n_R )}$

Error