«Previously, complete measurements of this type required actuation between measurements at different heterodyne phases,» he said. (sciencedaily.com)
The signal the researchers are trying to detect is very small so it must be amplified by spatially overlapping a reference laser beam that doesn't contain the signal of interest, which is a process called heterodyne amplification. (sciencedaily.com)
«Most complete measurements are made by collecting multiple measurements at different heterodyne phases (a measure of the path length difference) between the signal and reference oscillator to remove any systematic noise,» he said. (sciencedaily.com)