Liquid crystal modulators are a type of optical modulator which utilize liquid crystals to control the intensity, phase, or polarization of light. The operation principle is based on the birefringence of liquid crystals, where long molecules align to create anisotropic optical properties. Liquid crystals are liquids with anisotropic optical characteristics, meaning their refractive index varies based on the orientation of the optical electric field relative to the. Spatial Light Modulators SLM-S320(d) / 640(d) are linear array SLMs based on nematic liquid crystals and are proven tools for modulation of ultrashort laser pulses in the wavelength range 430-1600 nm.