Coherently coupled high-power fiber arrays

摘要: A four-element fiber array has demonstrated 470 watts of coherently phased, linearly polarized light energy in a single far-field spot. Each element consists single-mode fiber-amplifier chain. Phase control each is achieved with Lithium-Niobate phase modulator. A master laser provides polarized, narrow linewidth signal that split into five channels. Four channels are individually amplified using polarization maintaining power amplifiers. The fifth channel used as reference arm. It frequency shifted and then combined interferometrically portion channel's signal. Detectors sense the heterodyne modulation signal, an electronics circuit measures relative for channel. Compensating adjustments made to This effort represents results multi-year achieve high from amplifier understand important issues involved combining many individual elements obtain sufficient optical directed weapons. Northrop Grumman Corporation High Energy Laser Joint Technology Office jointly sponsored this work.