This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Snell law Positive and Negative Refraction. en Ray refraction between two mediums Positive index of refraction the transmitted ray in the second medium is placed on the opposite halfplane compared to the incident ray Negative index of refraction the transmitted ray in the second medium lays in the same halfplave as the incident