OM3 and OM4 fibers are compatible with each other in the sense that they can be connected and used within the same network. They have many things in common such as the fiber connectors and application scenarios, making them confusing to users. This post will illustrate the detailed. Two of the most widely deployed laser-optimized multimode fibers are OM3 and OM4, both designed to support high-speed data transmission using VCSEL-based optical modules. Performance depends on the lowest grade. OM4 is best for 10G–100G, OM5 supports SWDM. OM4 is another multimode fiber option, and in most cases, it also uses an aqua jacket (some companies use a purple jacket to distinguish it from OM3).