Abstract

Fiber lasers provide an attractive means of reaching high output laser power because of their advantages in terms of compactness, reliability, efficiency, and beam quality. Even given these advantages, it is desirable to increase the system power or energy levels beyond what is possible with a single-mode fiber laser. A promising technique is coherent beam combining with active phase locking involving phase detection and active compensation of phase errors [1]. In this Communication, we present coherent phase combining of 64 independent fibers, selectively amplified by 4 optical amplifiers. This is to our knowledge the highest number of combined fibers ever demonstrated. In order to achieve this result, we have developed specific collective components for phase measurement of a large number of fibers, arrays of phase modulators, and an array of collimated fibers.

© 2011 Optical Society of America