Patent ID: 8531675

Claim:
A Micro Electro-Mechanical System (MEMS) interferometer, comprising: a beam splitter formed on a first surface of a first medium at an interface between the first medium and a second medium and optically coupled to receive an incident beam and to split said incident beam into a first interfering beam propagating in the first medium and a second interfering beam propagating in the second medium; a first mirror formed on a second surface of the first medium and optically coupled to receive the first interfering beam and to reflect the first interfering beam to produce a first reflected interfering beam; a second minor formed on a third surface of the first medium and optically coupled to receive the second interfering beam and to reflect the second interfering beam to produce a second reflected interfering beam; tilt angle compensating surfaces of the first medium formed at respective additional interfaces between the first medium and the second medium in respective paths of the first interfering beam and the second interfering beam, each tilt angle compensating surface in one of the respective paths having a corresponding tilt angle compensating surface in the other of the respective paths such that the corresponding tilt angle compensating surfaces in each of the paths have a same tilt angle with respect to a plane of a substrate on which the MEMS interferometer is formed, at least one of the second surface and the third surface being one of the tilt angle compensating surfaces; a detector optically coupled to detect an interference pattern produced as a result of interference between the first reflected interfering beam and the second reflected interfering beam; and an electrostatic actuator coupled to one of the first mirror and the second minor to cause a displacement thereof, the displacement producing an optical path length difference between the first reflected interfering beam and the second reflected interfering beam equal to twice the displacement.