What are the commonly used wavelength selectors in the spectrophotometer?

Spectrophotometers use three main types of devices to select specific wavelengths: diffraction gratings, prisms, or colored filters. A diffraction grating is composed of closely spaced parallel grooves that cause light interference, resulting in the splitting of light into various wavelengths. In spectrometers, reflective gratings are commonly utilized to achieve this effect. A prism is a triangular piece of glass or quartz that disperses light by separating it into its component wavelengths based on their different refractive indices. A monochromator is a type of wavelength selector that operates by scanning through different wavelengths. Though initially relying on glass or quartz prisms, modern monochromators utilize holographic diffraction gratings designed using lithographic techniques similar to those utilized in creating computer chips. Filters are essentially colored pieces of glass that are used to isolate specific wavelength ranges. However, they're not widely used in UV-Vis spectrometry because they require frequent replacement to capture a full spectrum. Filters are a type of fixed wavelength selector based on the principle of constructive and destructive interference.