Self-aligned connections between single-mode fibers with mutually pumped phase conjugate mirrors

We demonstrate self-aligned connections at 633 nm between single mode fibers with two types of mutually pumped phase conjugate mirrors, made with photorefractive BTO crystals. The first type of device is the two-facing double phase conjugate mirror and the second is a double phase conjugate mirror, splitted into two zones. This second configuration provides higher efficiency and shorter response time (about 15 s). Up to 70% of the conjugated beam intensity may be coupled into the output fiber, while the total efficiency may reach 5%, mostly limited by crystal absorption. The influence of the period and orientation of the grating is experimentally studied. Reconfiguration capability is shown with reconfiguration time of a few tens of seconds. Efficient injection from a multimode fiber into a single mode one is also demonstrated. Possible applications of these self-aligned connections to free-space switching systems are suggested.