Optical module expansion cards are available in single-mode and multi-mode versions

Primary two types are single-mode SFP, or SMF SFP, and Multimode SFP, or MMF SFP. They are primarily built with LC connectors, which many call them as LC SFP transceivers. "What is the difference between single-mode SFP and multimode SFP, and which should I choose in 2026?" This article provides a full, modernized comparison including: Let's dive in. The SFP form factor has evolved far beyond the original 1G design. This means you can find combinations such as single-mode single-fiber modules or multi-mode dual-fiber modules： Most single-fiber modules are single-mode due to the complexity and cost of wavelength multiplexing in. An SFP module is a compact, hot-swappable optical transceiver designed to facilitate data transmission between network devices such as switches, routers, servers, and media converters. Often referred to as a “mini GBIC” (Gigabit Interface Converter), it replaces larger GBIC modules with a smaller. Single mode SFP (OS2) utilize a 9µm glass core for narrow-beam laser transmission, while Multimode SFP (OM3/OM4) employ 50µm cores for short-reach VCSEL links. Single mode delivers near-limitless bandwidth over distances from 10km to 80km, whereas Multimode serves as a cost-optimized 100m to 400m. Small Form-factor Pluggable (SFP) optical modules are widely used in networking to facilitate high-speed data transmission over optical fiber cables. Think of it as the “translator” for your network equipment, converting electrical signals into optical signals.