Abstract: The present invention provides a reflective condensing interferometer for focusing on a preset focus. The reflective condensing interferometer includes a concave mirror set, a convex mirror, a light splitting element, and a reflecting element. The concave mirror set has first and second concave surface portions which are oppositely located on two sides of a central axis passing through the preset focus and are concave on a surface facing the central axis and the preset focus. Light is preset to be incident in parallel to the central axis in use. The convex mirror is disposed between the concave mirror set and the preset focus on the central axis, and is convex away from the preset focus. The light splitting element vertically intersects with the central axis between the convex mirror and the preset focus. The reflecting element is disposed between the light splitting element and the convex mirror.

Abstract: The present invention provides a reflective condensing interferometer for focusing on a preset focus. The reflective condensing interferometer includes a concave mirror set, a convex mirror, a light splitting element, and a reflecting element. The concave mirror set has first and second concave surface portions which are oppositely located on two sides of a central axis passing through the preset focus and are concave on a surface facing the central axis and the preset focus. Light is preset to be incident in parallel to the central axis in use. The convex mirror is disposed between the concave mirror set and the preset focus on the central axis, and is convex away from the preset focus. The light splitting element vertically intersects with the central axis between the convex mirror and the preset focus. The reflecting element is disposed between the light splitting element and the convex mirror.