How to Test Optical Splitter Loss With Optical Power Meter & Light Source

Before discussing the details of splitter loss testing, here is a fact that we should know about it. Attenuation of signal through an optical splitter is symmetrical which means it is identical in both directions. Whether an optical splitter is combining signal in the upstream direction or dividing signals in the downstream direction, it still introduces the same attenuation to an optical input signal. Thus, the principle of optical splitter loss testing is to follow the same directions for a double-ended loss test.

 

Now, we test the simplest 1x2 optical splitter as the picture shown below. First, attach a launch reference cable to the optical light source of the proper wavelength (some splitters are wavelength dependent), and then calibrate the output of the launch reference cable with the optical power meter to set the 0dB reference. Attach to the light source launch to the splitter and attach a receive launch reference cable to the output and the optical power meter, and then measure the loss. Similarly, to test the loss to the second port—move the receive launch cable to the other port and read the loss from the meter. For the other direction from all the output ports, we should reverse the direction of the test.

 

For other 1xN optical splitters, e.g. 1x32 splitter, this test method can also be used. Just set the light source up on the input and use the power meter and reference cable to test each output port in turn. But for upstream, we have to move the light source 32 times and record the results on the meter.

 

So, how about the 2X2 splitter? In this case, a lot of data are involved sometimes but it needs to be tested. We would need to test from one input port to the two outputs, then from the other input port to each of the two outputs. In the same way, we can test other 2xN splitters.

 

Warm Tips: What you are measuring is the loss of the splitter due to the split ratio, excess loss from the manufacturing process used to make the splitter and the input and output connectors. So the loss you measure is the loss you can expect when you plug the splitter into a cable plant. Once installed, the splitter simply becomes one source of loss in the cable plant and is tested as part of that cable plant loss for insertion loss testing.

 

Conclusion

Optical splitters used in PON architecture are a very important type of passive optical components. Loss testing, as a necessary testing item of optical splitters can be done by using an optical power meter and light source. This tutorial illustrated the details of using optical power meter and light source to test optical splitter loss. Related products such as high-quality PLC splitters and testing tools such as optical power meter, light source and test cord are available in fiber-mart.COM with very affordable prices. For more details, please contact us over [email protected].