Abstract

Optical bistability and hysteresis in BaTiO₃ have been observed in a self-pumped ring resonator (SPRR). The SPRR can be controlled with an additional He–Ne laser erasing beam that makes an angle with the ring pump beam. The erasing beam could be coherent or incoherent with the pump beam. By injecting the erasing beam into the crystal in such a way as to partially erase the index grating and/or take energy from the pump beam, the coupling strength is modified. In either case, the output of the ring shows bistability and hystersis in the complete cycle of the on-off-on operation by monitoring the intensity of the erasing beam. The intensity change and the time interval between each change step of the erasing beam have effects on the hysteresis behavior. The hysteresis observed when it is controlled by a coherent erasing beam is more than the one by an incoherent erasing beam. Some fluctuations exist in the hysteresis loop when the coherent erasing beam is used.

© 1992 Optical Society of America