A device for use in an interferometer, and the combination thereof, the device itself combining the functions of filter, beam combiner, and modulator. In structure, the device includes a relatively small glass plate, which has deposited on opposite faces thereof two extremely small elliptical mirrors which each function as a reflecting spatial filter. In the improved interferometer which includes such a device, reference and signal beams are produced from a single coherent source. The signal bea...

Displacement measurement apparatus (1) shown in FIG. 1 measures the position of a reading means (4) relative to a coded track (2) which carries a sequence of code elements (5). The track is encoded with a binary sequence such that reading a binary word at any position along the track uniquely identifies its position. The binary word is remotely sensed by a decoding means (18) via a fibre optic link (12). Position information is encoded optically by the reading means using an interferometer to fr...

The present invention is directed to an improved unequal path interferometer which is a particularly adapted, among many other possible uses, for detecting coherent radiation in the presence of non-coherent ambient radiation, which comprises an unequal optical path length interferometer of the type in which portions of the radiation impinging on the interferometric component are caused to be recombined after travelling two different optical paths; the optical paths differing in length by an amou...

Apparatus for multiplexing fiber-optic sensing interferometers, which apparatus comprises at least one optical source, a plurality of matched interferometers connected to the optical source and each containing a phase modulator having a unique identifying characteristic, a network of fiber-optic sensing interferometers each containing a path-length difference, at least one detector, and interconnections provided between the matched interferometers, the network of fiber-optic sensing interferomet...

A laser strainmeter has a plurality of sensor resonators, each comprising a multiple reflection interferometer having a pair of concave mirrors (8) which are secured to the inner wall of a container (1) to face each other in the diametrical direction of the container so that the optical axes of the sensor resonators extend in different directions. The laser strainmeter further has a reference resonator comprising a multiple reflection interferometer having a pair of concave mirrors (12) which ar...

An asymmetrical interferometer having two Josephson junctions with unequal contact areas. In accordance with the invention, the magnetic flux magnitudes of the control lines of the Josephson junctions are approximately equal in each Josephson junction. In a preferred embodiment, the length of the Josephson junctions along a direction parallel to the control line are equal to each other. Moreover, each Josephson junction is provided with a counterelectrode metalization, the counterelectrode metal...

A plurality of interference length (distance) measuring means which are opposed to a movable mirror are aligned in the direction in which said movable mirror moves at an interval narrower than the length of the mirror surface. These interference length measuring means are switched according to movement of the movable mirror. Thus, the range within which distances from the mirror surface are measured can be made wider than the length of the mirror surface of the movable mirror.

The invention provides a method and apparatus for evaluating the quality of microelectromechanical devices having deformable and deflectable members using resonation techniques. Specifically, product quality characterized in terms of uniformity of the deformable and deflectable elements is inspected with an optical resonance mapping mechanism on a wafer-level.

A highly sensitive optical fiber interferometer sensor comprising a laser light source, a [2.times.2] optical fiber coupler to split the beam in two, a differential transducer which converts a signal of interest into optical phase shift in the laser light transmitted through the two optical fibers in the interferometer and a [3.times.3] optical fiber complex which recombines the two beams, producing interference which can be electronically detected. The use of the [3.times.3] coupler permits Pas...

A subject position adjusting apparatus for use with an interferometer has a leveling stand disposed on a stationary stand of the interferometer. A leveling standard is stationary relative to and extends upright from the leveling stand. The leveling standard carries a subject stage for up and down movement in an axial direction of a light beam. A leveling mechanism is disposed between the stationary stand and the leveling stand. The leveling mechanism controls the angle of the leveling stand rela...