Since the specification for OM5 multimode fiber (WB-MMF), users considering upgrading existing infrastructure or building new ones have asked the question: Should they deploy OM5 fiber?
OM5 fiber
First, let's discuss what exactly OM5 broadband multimode fiber is.
OM5 is essentially an OM4 fiber with additional bandwidth specifications at 953nm. Both OM4 and OM5 have a bandwidth of 4,700MHz·km at 850nm, while the bandwidth specification of OM5 is defined as 2,450MHz·km at 953nm. OM4 does not define a corresponding bandwidth specification at 953nm.
The OM5 is designed for short wavelength wavelength division multiplexing (SWDM) optical transceiver module applications. This new SWDM transceiver module uses four wavelengths, spanning from 850nm all the way to 953nm, enabling links that transmit 100Gbps.
Each wavelength will be modulated at 25Gbps, and by multiplexing these wavelengths, the entire link can be used for 100Gbps applications. Considering the wavelengths used in SWDM shortwave wavelength division multiplexing optical modules, it is very convenient to see why the OM5 standard was developed.
Notes: 1. Four laser light sources in Four Lasers; 2. Four detectors in Four Detectors; 3. The design of OM5 can be used for optical modules using short-wave wavelength division multiplexing.
OM5 standard
If you plan to deploy 100Gbps links using SWDM short wavelength wavelength division multiplexing optical modules and need to reach distances in excess of 100 meters, then only OM5 broadband multimode fiber needs to be considered.
The benefit of using SWDM shortwave wavelength division multiplexing optical modules is that such modules allow 100Gbps links to be deployed on duplex MMFs instead of the eight parallel fibers required when using 100GBASE-SR4. SWDM shortwave wavelength division multiplexing technology allows reuse of existing infrastructure based on duplex fiber optic transmission system components.
However, there are many more desirable alternatives to deploying 100Gbps on duplex fiber, such as 100G BiDi, or using PAM4 modulation to achieve higher data rates.
Other alternatives do not suffer from the inadequacies of SWDM shortwave wavelength division multiplexing optical modules, such as higher cost, operating temperature, and inability to support branching applications. If you are still considering SWDM 100G shortwave wavelength division multiplexing optical modules, and the transmission distance is within 100 meters, then a compromise solution is to use standard OM3 or OM4, because their price is lower than OM5.
If extended distances are required, say, with 40G BiDi, the best alternative to OM5 fiber is to use our OM4 Signature Core MMF. Our OM4 Signature Core MMF can reach 200 meters with 40G BiDi, while the OM5 can only reach 150 meters, the same as OM4.
The reason is that OM5 fiber does not perform better than OM4 at the wavelengths used by BiDi modules. In fact, the OM4 Signature Core has outperformed standard OM5 fiber in multiple head-to-head encounters with end users.
If the decision is to use a 100G SWDM shortwave wavelength division multiplexing optical module and you need to transmit more than 150 meters, then it is better to use our OM5 Signature Core MMF. The OM5 Signature Core MMF uses the same range-enhancing technology as the OM4 Signature Core, so you can take advantage of this 20% more range than the norm.
For an in-depth look at how our OM4 Signature Core and OM5 Signature Core MMFs can extend distances, visit Panduit's dedicated Fiber Solutions page, where you can find out all about Signature Core.
