Fiber – Can Optical Transceiver Be Permanently Damaged by Strong Rx Signal?

fiberopticstransceiver

Data sheets of optical transceivers often specify the receiver maximum input power. In addition, non-volatile memory of transceivers often seem to hold this data:

root@MX240> show interfaces diagnostics optics xe-11/3/0 | match "laser rx"
    Laser rx power                            :  0.7614 mW / -1.18 dBm
    Laser rx power high alarm                 :  Off
    Laser rx power low alarm                  :  Off
    Laser rx power high warning               :  Off
    Laser rx power low warning                :  Off
    Laser rx power high alarm threshold       :  1.2589 mW / 1.00 dBm
    Laser rx power low alarm threshold        :  0.0050 mW / -23.01 dBm
    Laser rx power high warning threshold     :  1.1220 mW / 0.50 dBm
    Laser rx power low warning threshold      :  0.0063 mW / -22.01 dBm

root@MX240>

I am aware that too strong Rx signal can saturate it for photodiode and as a result cause bit errors, but has anyone permanently damaged an optical transceiver(GBIC, SFP, XFP, SFP+) because of too strong Rx signal?

Best Answer

Your biggest risk comes from Single Mode ER (40 Km) and ZX (80 Km) optics, which can overdrive and even burn inputs without sufficient attenuation.

There is no risk of burning Multi Mode optics, as long as you're connecting MM to MM.