Fiber Optic Connector Coupling Loss versus Light Wavelength

Single mode optical connectors work with both 1310nm and 1550nm, but the coupling loss is very different between these two wavelengths.

The loss in decibels at a connector is about 7% greater at 1310nm than at 1550nm, based on measured data. And some equations were developed which is pretty consistent with actual measurement result.

The conclusion is simple: the loss in a connector is slightly larger at shorter wavelengths.

The coupling loss calculation equations involve more than wavelength, mode field diameter and refractive index also plays important role which makes the loss calculation a much more complex function of wavelength.

Here are some actual measurement result just to show the fact.