A spatial light modulator is a device that allows for the modulation of light waves in two dimensions. It is commonly used in applications such as digital holography, optical trapping, and adaptive optics. Spatial light modulators can be based on technologies such as liquid crystal displays (LCDs), deformable mirrors, and digital micromirror devices (DMDs). By controlling the intensity, phase, or polarization of light waves at specific spatial points, spatial light modulators enable the manipulation and control of light in various optical systems.