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?