Fiber optic patch cords are divided into two main types

Fiber optic patch cords are classified by fiber type, connector type, cable configuration, and polish type, each suited for specific applications and transmission requirements.1. Fiber TypeFiber optic patch cords are primarily divided into single-mode (SM) and multimode (MM) fibers.Single-mode (SM): Features a small core (~9µm) allowing only one light path, suitable for long-distance communication with low attenuation. Common standards include OS1, OS2, and bend-insensitive G.657A1/A2 fibers .Multimode (MM): Has a larger core (50–62.5µm) supporting multiple light paths, ideal for short-distance, high-bandwidth applications. Standards include OM1 (orange), OM2 (orange), OM3 (aqua), OM4 (violet), and OM5 (lime green) fibers .2. Connector TypePatch cords are also classified by the connector at each end, which ensures precise optical alignment:LC (Lucent Connector): Small form factor, duplex, widely used in high-density data centers .SC (Subscriber Connector): Square, snap-in, common in telecom networks .ST (Straight Tip): Bayonet mount, rugged, used in industrial or legacy LANs .FC (Ferrule Connector): Screw-on, suitable for high-vibration environments .MPO/MTP: Multi-fiber connectors for high-density parallel optics (8, 12, or 24 fibers), essential for 40G/100G data center links .Other types include MU, MT-RJ, and E2000 connectors, each with specific use cases .3. Cable ConfigurationPatch cords can be simplex or duplex:Simplex: Single fiber, used for one-way communication like transmit-only or receive-only applications .Duplex: Two fibers, supporting two-way communication, common in high-speed networks .4. Polish TypeThe ferrule end-face polish affects signal quality and return loss:PC (Physical Contact): Slightly spherical, reduces air gap, RL ~−40dB .UPC (Ultra Physical Contact): Extended polish for better surface finish, RL ~−55dB .APC (Angled Physical Contact): 8° angle to minimize back-reflection, ideal for high-performance digital applications .5. Jacket Material and Environmental ConsiderationsPatch cords are also classified by jacket type for installation environments:PVC: Standard indoor use.Plenum (OFNP): Fire-resistant, safe for air ducts.Riser (OFNR): For vertical shafts between floors.LSZH (Low Smoke Zero Halogen): Emits minimal smoke/toxic gas, common in Europe and high-safety areas .SummaryFiber optic patch cords are classified based on fiber type (SM/MM), connector type (LC, SC, ST, MPO, etc.), cable configuration (simplex/duplex), polish type (PC, UPC, APC), and jacket material. Selecting the right combination ensures optimal performance, low signal loss, and suitability for specific applications such as long-haul telecom, data centers, or industrial networks .