Optical flip-flop based on a multiple cavity ring laser with feedback

We present a novel concept for optical bi-stability that exists in a ring laser with two separate but coupled cavities that operate at different wavelength. We show that lasing light in each of the cavities can suppress lasing in the other cavity so that this configuration forms an optical bi-stable element. Essential in the operation is the presence of feedback of the lasing light. We show that this configuration can be optically set and reset, has a contrast ratio of over 40 dB and allows low optical power operation