Phase-locked Fiber Lasr Array

The purpose of this Phase II effort is to build a rugged, compact optical phased array for coherent addition of laser beams, a crucial building block for multi-kilowatt continuous wave laser devices. This effort builds on the success of the Phase I effortwhere it was shown that an array of electro-optic waveguides in Potassium Titanyl Phosphate (KTP) could be used for phase control. The low-voltage device can control the phase of each laser beam utilizing individually addressable waveguides that areseparated from each other by 250 mm. A phase front sensor will be used to provide a feedback system for coherent addition of the output laser beams. The completed device will be connectorized so components such as high-power fiber amplifiers can be easilyinserted or replaced. Because multiple phased array modules can be cascaded and operated in parallel, the technology is highly scalable. Additionally, the KTP waveguides are transparent across a spectral range from 350 nm to 4500 nm, allowing thistechnology to be used for the generation of high-power laser beams at numerous wavelengths using currently available laser amplifiers. This will enable or improve high-power laser applications for the military, medical, laser machining, and scientificcommunities.