Implications of higher-order mode content in large mode area fibers with good beam quality

The impact of Higher-Order Mode content on beam quality in large mode area fibers supporting several guided modes is carefully investigated. It is shown that even excellent beam quality (M(2) < 1.1) in LMA fibers does not guarantee low HOM content, and that the presence of HOMs can lead to significant uncontrollable changes in beam quality, peak intensity, and pointing uncertainty that depend on the uncontrollable relative phase of the modes in the fiber.