Prism-based beam steering

The difference between Gg and Go is the steering angle. The prism with a larger birefringence would lead to a larger steering angle. 

Let us assume that the refractive indices of the birefringent prism (it can be a crystal or liquid crystal) are ng=. l and = 1.5. Then, in order to get 1° steering angle, the required prism angle should be 5°. By stacking N basic units whose a values are in binary sequence, then 

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