There are fiber bundles which are specially optimized for transmitting light from high-power lasers, sometimes with the ability to transport several kilowatts of optical power. Some of them are made from copper-coated multimode fibers, where the copper metal layer helps to. Thorlabs offers multimode fiber bundles in straight, bifurcated (Y-cable), or fan-out configurations and round or linear bundle end configurations. Our stock fiber optic bundles are terminated with SMA905 connectors and are offered with high OH fiber, low OH fiber, and our mid-IR fluoride optical. FiberTech Optica delivers fiber optic bundles to meet almost any requirement. One usually applies a polymeric coating and further protection layers around the whole bundle, e. a sleeve or flexible tube, often made of stainless steel.