Quantum Noise & Effective Noise Temperature

9006-016

This graph shows how the effective noise temperature for optical heterodyne receivers is much greater than for their microwave counterparts. This is one of the reasons some MSETI researchers use to justify their objections to the microwave approach. However, the much higher gains of optical uplinks more than makes up for the higher noise temperatures of optical receivers.

The Columbus Optical SETI Observatory
Copyright (c), 1990