In some optical systems, linearly polarized light is undesirable, such as in reflection spectrometers, where polarization effects can affect detector sensitivity. Depolarizers are used to convert polarized light into unpolarized light. They are widely used in systems and instruments that are sensitive to polarization. The usual depolarization device can only be used in a relatively narrow spectral range due to the limitation of the beam deviation angle. This depolarization device can be used in a wide spectral range and controls the beam deviation angle within an acceptable range.