Multimode versus Singlemode

Figure 1: Cross-sections of Multimode and Singlemode fibers

Figure 1: Cross-sections of Multimode and Singlemode fibers

For many years now we at Optical Systems Design have been promoting the major technical and economic advantages of singlemode fiber versus multimode.

Very often, it unfortunately seems that typical singlemode equipment is much more expensive that the equivalent multimode gear.

However, as surprising as it may appear, the much higher performance singlemode fiber and cable has for at least 20 years been substantially lower cost than multimode primarily due to its simpler structure (resulting in faster manufacturing time) and its vastly greater volume of production.  Consequently, in the past there has often been a trade-off possible between the cost of singlemode gear and the lower cost of SM cable with the changeover point from a multimode system to a singlemode system typically occurring somewhere between 500 and  1500 meters.

This juggling act is finally becoming unnecessary: OSD’s latest range of digital video and Ethernet products are the same price for either fiber type so you get all the technical advantages of SM as cost effectively as MM.  Furthermore, we intend to continue with this trend for almost all new OSD products. You can expect to pay the same or less for a singlemode product as for the multimode version. Often, the product will, in fact, be the same unit: a major advantage when you have a legacy network with a mix of SM and MM fibers.