Multimode fiber is cheap

Multimode fiber is generally less expensive than single-mode fiber due to its larger core, compatibility with cost-effective light sources, and simpler installation requirements.

Why Multimode Fiber Is Inexpensive

Larger Core Diameter: Multimode fiber has a core size of 50 or 62.5 micrometers, which allows light to travel along multiple paths. This larger core makes it easier to align connectors and reduces the precision required during installation, lowering labor and equipment costs . Affordable Light Sources: Multimode fiber can use LEDs or VCSEL (Vertical-Cavity Surface-Emitting Laser) transceivers, which are significantly cheaper than the specialized lasers required for single-mode fiber. VCSELs, in particular, provide high-speed performance at a lower cost, making multimode fiber ideal for short-distance, high-bandwidth applications . Short-Distance Optimization: Multimode fiber is designed for distances typically under 500–550 meters, such as within data centers, office buildings, or campus networks. Its cost-effectiveness comes from the fact that it avoids the need for expensive long-reach optics and ultra-precise alignment required for single-mode fiber . Installation and Maintenance: The forgiving nature of multimode fiber connectors and alignment reduces installation complexity and maintenance costs. While longer runs may require additional equipment to manage modal dispersion, for typical short-range deployments, multimode fiber remains a budget-friendly choice .

Practical Considerations

• Performance vs. Cost: While multimode fiber is cheaper, it has shorter reach and lower maximum bandwidth compared to single-mode fiber. For networks where future scalability and long-distance transmission are critical, single-mode fiber may be a better long-term investment despite higher initial costs .
• Common Applications: Multimode fiber is widely used in data centers, campus networks, AV setups, and interbuilding connections where cost and ease of installation are priorities .
• Modern Standards: OM3, OM4, and OM5 multimode fibers are optimized for VCSEL-based transceivers, supporting high-speed Ethernet (10G, 25G, 40G, 100G) over short distances while maintaining cost efficiency . In summary, multimode fiber is inexpensive primarily because of its larger core, compatibility with affordable light sources, and simpler installation, making it the preferred choice for short-range, high-density network environments where budget is a key factor.