Innovations in Optical Fiber Technology
Optical fiber can provide numerous advantages over other transmission media, such as twisted-pair copper and wireless technology. For example, because space is always at a premium, high-density fiber-optic systems may be preferred for maximizing valuable square footage. Fiber’s small size and weight require less space in cabling pathways, raised floors and equipment racks.
Other advantages of optical fiber include:
- Greater bandwidth and error-free transmission over longer distances
- Simpler testing
- Immunity to EMI/RFI
Video: Innovations in Optical Fiber Technology
Migration Path to 40 and 100 Gigabit Ethernet
Two-fiber (duplex) transmission is a common optical infrastructure technology used in today’s data center and commercial intrabuilding cabling backbones. Two-fiber implementations can use either multimode or single-mode optical fiber media. Multimode infrastructure has the advantage of lower-cost optics that drive a lower overall system cost, compared with the more expensive single-mode optics that offer significantly longer-distance support (in the order of kilometers). In many instances, the shorter reach associated with multimode optical fiber is sufficient to support the higher speed 40 Gigabit Ethernet and 100 Gigabit Ethernet systems. However, careful planning is vital because these systems use parallel optical technology with multiple fiber strands to send and receive data. In order to understand the migration from two-fiber transmission to multi-fiber parallel optical transmission, Figure 1 below helps outline the optical and connector configurations in each scenario.
Figure 1 – Optical and Fiber Connector Configurations
Cabling and Infrastructure
The lower system costs that are a principal benefit of multimode optical fiber solutions has made it an attractive choice for high-speed data communications, but improved simplification of the associated cabling infrastructure is an ongoing objective of the industry standards committees. In 2015, the IEEE 802.3 LAN/MAN Standards Committee (LMSC) published the IEEE 802.3bm, “Standard for Ethernet Amendment: Physical Layer Specifications and Management Parameters for 40 Gb/s and 100 Gb/s Operation Over Fiber Optic Cables,” which defined a four-lane/8-fiber 100 Gigabit Ethernet interface (100GBASE-SR4) that will simplify the migration from 40 Gigabit Ethernet to 100 Gigabit Ethernet over multimode fiber in the data center utilizing OM3 or OM4 cabling.
New development work is underway to reduce the fiber count further with the publication of the Telecommunications Industry Association (TIA) standard TIA-492AAAE, which defines the performance specifications for wideband multimode fiber otherwise known by OM5 designation. By utilizing four discrete wavelengths within the 850-950 nm range coupled with short wavelength division multiplexing (SWDM) optical technology, OM5 has the capability to reduce the fibers necessary for 40Gb/s transmission from four-lane/8-fiber to a single-lane/2-fiber solution. SWDM optics standardization efforts are being conducted by the IEEE 802.3cd “50 Gb/s Ethernet Over a Single Lane and Next Generation 100 Gb/s and 200 Gb/s Ethernet” Task Force.
Figure 2 - OM5 enables high speed via duplex fiber (SWDM)
As the amount of data that is being generated by both computing hardware and mobile devices continues to grow unabated, optical fiber technology will continue to evolve with new and innovative product solutions.