Abstract: This invention relates to a phased-array laser oscillator/amplifier system consisting of looped fibre lasers whose two optically polished end faces are stacked together to form a single output aperture near to which is positioned a single laser mirror in the case of the laser oscillator configuration of the invention or an optical window in the case of the laser amplifier configuration, which is index-matched to said output aperture, the said fibre bundle laser medium being optically excited via the said single aperture composed of the fibre ends. In the case of the laser oscillator configurations of the invention, the single laser mirror is partially transmitting and allows the output laser beam to emerge as a phase-locked beam formed by adding together all the outputs from the individual fibre laser ends.

Abstract: A phase-locked fibre bundle laser oscillator made up of one or more active fibre loops as illustrated. The single mode fibre has a doped core surrounded by cladding and has its ends positioned in a common plane forming a two core aperture which is optically polished to a twentieth wavelength. Fibre end faces are coupled by index matching material to a single, partially transmitting, dielectric mirror and the oscillator is side pumped via the output of an array of laser diodes.