OFS Develops Solutions for Diverse Military Applications

Military applications can be some of the most fascinating for specialty optical fibers and the connectorized cables into which they are made. The military’s almost-constant need for better, stronger, faster has resulted in futuristic ideas becoming reality at a staggering pace. Specialty optical fiber, cable, gratings and value - add assemblies from OFS are key components of many of today’s most sophisticated military systems. Take a look at some of the applications enabled by focused fibers solutions from OFS:

Fiber optic towed decoys are an electronic countermeasure that protects military aircraft from surface-to-air and air-to-air missiles by sending false signals that lure the missile away from the aircraft by creating a new target. When a missile is detected, the decoy is deployed rapidly to trail behind the aircraft and send signals that are picked up by the missile. Fiber optic cable carries these signals from an onboard controller to the decoy. OFS supplies high strength, bend-insensitive optical fiber, with special coatings for hermeticity, abrasion resistance and wide temperature performance.

Hydrophones are underwater acoustic sensors that are used by the military in a variety of applications. These listening devices detect acoustic energy underwater using interferometric sensor technology to measure acoustic pressure. Arrays are sets of hydrophones that are linked together and can be deployed in different ways. Conformal arrays can be molded to a ship’s hull. Linear arrays can be towed behind a ship in long cables or placed on the ocean floor. For these applications OFS supplies bend insensitive fibers with 80 mm clad diameter vs the 125 mm cladding found in standard optical fibers. This reduced size gives better mechanical bend performance. Next-generation hydrophones utilize fiber Bragg gratings for even greater acoustic sensitivity. OFS has developed and patented a write-through coating that allows many gratings to be written in a single length of fiber without the strip and recoat steps normally associated with grating fabrication.

Time Delay Coils, supplied by OFS, are a sub-component of Fiber Optic Delay Lines that are used in radar systems and in military early warning equipment. Optical fiber coils are replacing coaxial cable and bulk acoustic wave technology in applications such as radar calibration, phased antennae array and signal processing. Optical fiber in these applications has the advantage of wide bandwidth, low loss, linearity of phase response, and excellent signal quality. OFS can tailor the length of the coil to the exact time delay required and perform accurate winding on cus tom ized spools.

Aircraft Communications Systems are made more reliable with OFS Flightguide^® Cables. These products are a family of cables designed and qualified specifically for use in aircraft. OFS offers a selection of multimode and single-mode fibers in this construction, providing choices for system designers. As aircraft communications systems become more sophisticated and employ WDM systems, a migration from multimode to single-mode will take place. OFS fibers supply the optical performance, bend resistance, and high mechanical reliability needed. All the fibers have a primary layer of carbon coating for hermeticity followed by an optional polyimide coating followed by silicone, and then a buffer of ETFE. Further protection is provided with a layer of braided aramid yarn and a 1.8 mm diameter ETFE jacket.

Tomorrow’s Applications: OFS Laboratories play an important role in supporting military research and development in optical fibers, photonic devices, and systems. Research is being conducted in a wide variety of areas, including radiation hardened fibers (for fibers that must endure the intense radiation environments inherent in outer space deployment and high-flying jet systems), fiber lasers, microstructure fibers, rare earth doped fibers, highly non-linear fibers, broadband supercontinuum sources, fiber sensors (biological, chemical), Bragg gratings and grating arrays, long period gratings, higher order mode DSCMs, and beam expanders.

This is just a sampling of the active applications and research areas OFS works with everyday. By necessity, much of our research on technologies and products for military use must remain secret, so details are not disclosed. But the general types of applications listed here give an idea for the breadth of application possible when combining the inherent advantages of specialty optical fibers with the experience and expertise of OFS scientists and engineers. Also, many applications once considered cutting edge and unique to the military eventually find their way into applications in industry and civilian life. Keeping tabs (to this limited extent) on what the military is up to, then, proves to be both eye opening and thought provoking.