This is the lowest value recorded during the current performance-monitoring interval of the combined received optical power across all optical lanes of this multi-lane coherent port during the current performance-monitoring interval. The lowest combined power seen in the interval matters most for the port as a whole, since a dip here (even if one lane's reading alone looks fine) can still indicate an overall input power problem such as a bad connector at the port level. For example, if inOpticalPowerLaneTotalMin falls close to the port's receiver sensitivity floor, an admin would prioritize inspecting the port-level connector before diving into per-lane diagnostics.