The Sagnac effect: interference in a rotating frame of reference.

The phenomenon of interference has great importance in understanding the wave properties of light. Here, we demonstrate the effect of a moving reference frame on an interference pattern by building a simple Sagnac interferometer, without the burden of using optical fibres. A generalized theoretical derivation for an arbitrarily shaped interferometer is given, and the Sagnac effect is demonstrated in a simple laboratory setup. [ABSTRACT FROM AUTHOR]