Light emitted from a coherent light source undergoes fine adjustment of its polarizing direction by a polarizing device and is directed to a liquid crystal device through a collimating optical system. The polarizing device is capable of fine-adjusting the polarizing direction in accordance with the wavelength of the incident light, thereby providing a high contrast ratio. When an image is recorded by holography using such a liquid crystal spacial light modulator, it is possible to obtain an image of high quality.