When measuring Optical Return Loss (ORL) on a single-mode video link, the meter reads 20 dB. The specification requires 45 dB. What does the 20 dB reading indicate?

Question

When measuring Optical Return Loss (ORL) on a single-mode video link, the meter reads 20 dB. The specification requires >45 dB. What does the 20 dB reading indicate?

Accepted Answer

There is a highly reflective connector or poor splice causing massive reflection back to the source. ORL is measured in positive dB representing the amount of attenuation the reflected signal experiences. A low number (20 dB) means very little attenuation of the reflection, meaning a LOT of light is bouncing back. It needs to be >45 dB.

Answer

The transmitter is overpowered

Answer

The fiber is broken perfectly clean in the middle of the run

Answer

The link has an excellent return loss and passes easily

When measuring Optical Return Loss (ORL) on a single-mode video link, the meter reads 20 dB. The specification requires >45 dB. What does the 20 dB reading indicate?

Courses that include this