How Space Plasma Can Bend the Laser of Gravitational Wave Detectors

This schematic of the receiver plane illustrates the definition of the laser deflection angle and the laser transverse displacement. The ideal laser beam should be parallel to the z-axis and pass through the intersection point of the x- and y-axis. However, when the real laser beam passes through the space plasma, it generates a deflection of the laser direction (red dashed line) and a displacement of the beam center (red cross). This can introduce pointing accuracy noise in the gravitational wave detection. Credit: Zhou et al. [2026], Figure 2