Cisco SFP-10G-LR minimum distance

Cisco SFP-10G-LR module is capable of working with a link length of up to 10 km on any basic single-mode fibre. It complies with the 10GBASE-LR standard and uses 1310nm lasers. In this article Cisco SFP-10G-LR module is based on EDGE Optic’s part numbers 10G-SFP-10 (10km version) and 10G-SFP-20 (20km version), and all technical assumptions are based on EDGE Optic’s module parameters. It has the following optical parameters from EDGE Optic’s matching product 10G-SFP-10:

Parameters for 10G-SFP-10

As we see maximum transmitting power is -8.2 dBm, and receiver overload starts at 0 dBm. Based on this, if we were to make a connection using short-distance single-mode cable, even a couple of meters, it wouldn`t do any harm and would not burn down the receiver side laser.