PHYSICS · Multi-part · Fermi University Physics · Optics & Photonics · Geometrical optics and imaging · Geometrical optics and imaging
Optics and Photonics, Ch Image formation by mirrors and lenses
Problem
One end of a long solid glass light-pipe, of refractive index n=1.50, is ground to a convex hemispherical cap of radius R=2.0cm. Using this chapter's sign convention (light travels left to right; R>0 when the centre of curvature lies to the right of the vertex), a small point source of light is placed in air on the axis in front of the cap.
((a)) How far in front of the cap must the source sit for the light inside the rod to travel parallel to the axis?
((b)) The source is placed 8.0cm in front of the cap. Find the image position, and state whether the image is real or virtual and whether it lies inside or outside the rod.
((c)) The source is moved in to 2.0cm in front of the cap. Find the image position and say what its sign tells you.