Abstract: A curved prism array applied to an infrared sensor wherein: the infrared sensor comprises at least an infrared sensing element which is used in detecting infrared signals within a solid-angled FOV and installed inside the curved prism array; the curved prism array has an incident focal plane and a plurality of emergent focal planes, both of which are not parallel with each other, such that infrared signals beyond the solid-angled FOV are received by the incident focal plane, refracted through one of the emergent focal planes and guided toward the infrared sensing element for expansion of the solid-angled FOV of the infrared sensing element.