10. Holography - explanation of the principle of operation. (2p.)

Question 1

Holography - explanation of the principle of operation.

Answer 1

An ordinary photograph records only the intensities of the waves coming from different parts of the scene. So the information on the amplitudes of the waves is preserved on it, whereas the information on their relative phases is lost.

Holography technique was invented to preserve both the amplitudes and the phases of the wave fronts on a photographic plate, called a hologram. Whereas a photograph projects a threedimensional object onto a twodimensional format, a hologram preserves the information on the threedimensional nature of the object.