Polarization-maintaining, large-effective-area, higher-order-mode fiber.

Higher-order-mode (HOM) fibers guiding light in large-effective- area (Aeff) Bessel-like modes have recently generated great interest for high-power laser applications. A polarization-maintaining (PM) version of HOM fibers can afford the added possibility of coherent beam combination, improved material processing, and polarization multiplexing of high-power fiber lasers. We report a PM-HOM fiber for guiding Bessel-like modes with Aeff ranging from 1200-2800 mu m(2). The fiber modes exhibit a birefringence value that compares well with that of a conventional single- mode PM fiber (2 x 10(-4)), and exhibit a polarization extinction ratio ranging from 13-23 dB over meter-long fiber lengths, practical for amplifier systems. This fiber presents a unique platform for next-generation high-power fiber systems, as well as for the fundamental studies on deterministically polarized Bessel-like modes in fibers. (C) 2017 Optical Society of America