OFS (Avon, CT) has developed a new Hollowcore Fiber (HCF) as part of the DARPA-funded Compact Ultra Stable Gyro for Absolute Reference (COUGAR) program, led by Honeywell International, Inc. The breakthrough fiber employs an air filled core surrounded by glass webbing. Hollow-core fibers allow light to propagate through free space rather than a solid glass core, making them an ideal waveguide in theory.
Earlier versions of HCF showed high propagation speeds, but certain limitations prevented the breakthrough performance promised. This fiber overcomes these limitations and dramatically improves three critical performance enabling properties: single-spatial-mode: breakthrough “PRISM” mechanism forces light to take only a single path, enabling higher bandwidth and lower noise over longer distances; low loss: light maintains power over longer distances; and polarization control: the orientation of the light waves is fixed in the fiber, which is necessary for applications such as sensing, interferometry and secure communications.