Optical device with entrance and exit paths that are stationary under device rotation

摘要

An rotating optical device in which the angular relationship of the exit beam to the incident beam is independent of the degree of rotation of the device. Two optical elements are defined by planes that intersect at a 45 DEG angle. A third optical element is defined by a plane that bisects the 45 DEG angle. The device is rotated about the line included by all three planes. In an embodiment of the device configured as a Sagnac interferometer, the first two optical elements are reflectors and the third element is a beamsplitter. Preferably, up to eight such interferometers are mounted on the same rotating platform and with the same rotational axis, for extended spectral bandwidth. The scope of the invention also includes spectral imaging devices based on such interferometers.