Once through the lens, the ray should pass through the principal focus. Draw a ray which passes from the object through the centre of the lens. Some ray diagrams may also show a third ray.

Draw a ray from the object to the lens that is parallel to the principal axis. Once through the lens, the ray should pass through the principal focus. Draw a ray which passes from the object ...

The bifocal lenses are made from bilayer structures of liquid crystal (LC) cells and LC polymer. These lenses split light with a left-handed circular polarization (LCP) into two focused light ...