What is an unsheathed optical cable

Unsheathed optical cable is a bare fiber strand without protective outer jacket, primarily used for light transmission in decorative or endpoint applications.OverviewUnsheathed optical cables, also known as raw or end-point fiber, are individual strands of fiber optic material sold without a protective PVC or other outer jacket ( ). These fibers are designed to transmit light from a source, such as a fiber optic light engine, rather than generate light themselves. They are commonly used in decorative lighting, starfield ceilings, signage, chandeliers, fountains, and garden installations ( ).Construction and MaterialsCore Material: Typically polymethyl methacrylate (PMMA), which is transparent and allows efficient light transmission ( ).Cladding: Low refractive index material, often high-transparent fluorine resin, to contain light within the core ( ).Diameter Options: Available in a range of sizes, commonly from 0.25mm to 3mm for single strands, with larger diameters available on request ( ). Unlike sheathed cables, unsheathed fibers lack a protective outer layer, making them more flexible but also more fragile. They cannot bear heavy loads and require careful handling to avoid breakage ( ).ApplicationsUnsheathed optical cables are ideal for endpoint lighting, where light is emitted primarily from the fiber ends. Typical uses include:Starfield ceilings and wall displaysDecorative chandeliers and interior lightingWater features like fountains and waterfallsCar interior or garden lightingCustom fiber bundles for artistic or architectural projects ( )Handling and InstallationLight Source Required: Unsheathed fibers need a separate light engine to function ( ).Bending Limitations: Care must be taken to respect the fiber's bend radius to prevent attenuation or breakage ( ).Temperature Range: PMMA fibers can operate from -55°C to +70°C in low humidity, but may become brittle at lower temperatures ( ).Termination: Single strands often require no termination, while multi-strand bundles may use ferrules or soft silicone tips for secure attachment to fittings ( ).AdvantagesFlexibility: Easier to route in tight spaces compared to sheathed cables.Customizability: Allows creation of bespoke fiber bundles for specific lighting designs.Cost-Effective: Purchasing unsheathed fiber by the spool is generally more economical than pre-sheathed bundles ( ).LimitationsFragility: More prone to damage without protective sheathing.No Load-Bearing: Cannot support weight or mechanical stress.Requires Light Engine: Cannot emit light independently. In summary, unsheathed optical cables are specialized fibers for transmitting light in decorative or endpoint applications, offering flexibility and customization but requiring careful handling and an external light source for operation ( ).