Abstract

In a mode-locked ring laser the counter- propagating pulses are used to measure nonreciprocal phase differences of 10^-6. When the pulses are combined outside the cavity on a detector, a beat note that represents the difference in the longitudinal mode spacing (or phase difference) for the two counterpropagating fields is observed. This difference in longitudinal mode spacing can be realized by having nonreciprocal effects, such as rotation,¹ or by placing matter in the cavity.

© 1995 Optical Society of America