Coherent combining of fiber lasers using a ring coupled cavity and single-mode fiber filtering

Coherent combining of two fiber lasers has been experimentally demonstrated by using a ring coupled cavity and single-mode fiber filtering technique. Their phases are primarily synchronized due to mutual injection coupling introduced by a common ring coupled cavity, and efficient phase locking is realized by utilizing a single-mode feedback fiber to filter the far-field pattern. The detailed experimental investigations indicate that the stability of phase locking can be improved significantly by this spatial filtering technique, and the far-field intensity distribution can be manipulated by controlling the position of the filtering fiber.