Gould Inc.

David W Stowe

Paul M Kopera

John D Christian, Deceased

David A Christian, Heir

By Albert Christian, Heir

By David Christian, Heir

Ann L Ziegler, Heir

By Ann Ziegler, Heir

By Martha Christian, Heir

Albert Christian, Heir

Martha R Christian, Heir

An optical coupler and method of making same is described. The coupling ratio of the coupler is polarization-insensitive. The optical coupler described herein is made from single-mode optical fibers. Each optical fiber has a length of nearly exposed core which is fused to the exposed core of the other optical fiber while the fibers are maintained in parallel juxtaposition with one another without twisting. By creating a fused core coupler from single-mode optical fibers in which the cores are in parallel juxtaposition with one another, the coupling ratio of the subject invention does not change with changes in polarization of light passing through each single-mode fiber and, thus, is polarization insensitive.

Method of making a polarization-insensitive, evanescent-wave, fused

A star coupler is described in which a plurality of optical fibers are embedded in a first rigid substrate. The fibers may be etched or polished to a core area to expose a first evanescent coupling zone. A second substrate has one or more optical fibers embedded in the second substrate. The optical fibers in the second substrate are similarly etched or polished to expose a second evanescent zone area. The two substrates are then placed in juxtaposition with each other so that the first and second evanescent zones are in close proximity to one another so that evanescent coupling may occur between the plurality of fibers in the first evanescent zone and one or more optical fibers in the second evanescent zone.

Evanescent-wave star coupler on a substrate

An optical interferometer matrix is described which includes a reference waveguide for optically transmitting a reference signal. The optical interferometer matrix further includes a signal source waveguide for optically transmitting a source signal which has been modulated with respect to the reference signal in response to an applied physical effect. The physical effect may be, for example, thermal, acoustic, hydrodynamic, electrical, electromechanical or magnetic. The reference and signal waveguides are then optically coupled to one another at two different points so that interference between the light in the waveguides occurs under two different phase conditions, with a phase difference between these conditions which approaches .pi./2 radians. In the preferred embodiment, the two points of optical coupling are confined in a small space so that thermal- or pressure-induced differential phase changes of light between the first and second coupling points are negligible.

Quadrature fiber-optic interferometer matrix

An adjustable coupling device for fiber-optic power dividers in which the coupling characteristics of the divider are influenced by application of transverse forces on the optic fibers in a repeatable fashion. The preferred embodiment consists of a pair of optical fibers which are evanescently coupled by having a portion of each etched to a core and twisted about the other. The etched and twisted portions of these fibers are encased in a rigid housing filled with an elastic filler material. Means are provided for creating forces in the filler material which are transverse to the fibers.

Adjustable coupling device for a fiber-optic power divider

Optical devices having one or more rigidly supported optical fibers and a method of making thereof are provided in which one or more optical fibers are interfaced with a rigid support material by molecular restructuring of interfacing surface areas of the fibers and the support material. The rigidly supported optical fiber may be fabricated by assembling a longitudinal outer surface portion of the fiber in juxtaposition with a rigid support material having a lower melting point than the fiber. This assembly may be heated to allow partial softening of the support material along the outer surface of the fiber to allow fusing therebetween. The assembly may then be cooled below the melting point of the support material to provide a ruggedized fiber-optic assembly comprising an optical fiber fused to a rigid support material. Various optical devices may be formed from combinations of such rigidly supported optical fibers.

Optical fiber apparatus including subtstrate ruggedized optical fibers

Optical devices having one or more rigidly supported optical fibers and a method of making thereof are provided in which one or more optical fibers are interfaced with a rigid support material by molecular restructuring of interfacing surface areas of the fibers and the support material. The rigidly supported optical fiber may be fabricated by assembling a longitudinal outer surface portion of the fiber in juxtaposition with a rigid support material having a lower melting point than the fiber. This assembly may be heated to allow partial liquification of the support material and fiber along the outer surface of the fiber to allow fusing therebetween. The assembly may then be cooled below the melting point of the support material to provide a ruggedized fiber-optic assembly comprising an optical fiber fused to a rigid support material. A nonstick mold material also may be provided during assembly which has a substantially higher melting point than either the fiber or the support material. The mold may be placed in juxtaposition with the fiber to prevent the fiber from being totally embedded in the support material. Various optical devices may be formed from combinations of such rigidly supported optical fibers.

Substrate ruggedized optical fiber apparatus

An interferometer is disclosed for optically sensing displacements in a surface. A first fiber optic waveguide receives light from a laser in one end and transports it to the other end where a portion is back reflected and a portion is projected upon the surface. The reflected light from the surface re-enters the fiber optic at the projecting end and combines with the back reflected signal to derive an optical information wave. This optical information wave is evanescently coupled to a second fiber optic waveguide which transports this wave to a detector. A specific amount of reflective matter is attached to the end of the first fiber optic waveguide to enhance reflection therefrom, and an optical energy absorber is fixedly attached to the other end of the second fiber optic waveguide to prevent internal back reflection within the second fiber optic waveguide.

Fiber optic interferometer

An optical transducer (10) having a plurality of concentric cores (15,17). An intermediate cladding (16) is disposed between the inner and outer cores and an outer cladding (18) surrounds the outer core to define a symmetrical cylindrical transducer structure. Light propagated through the inner core (15) from a source (19) is coupled into the outer core (17) as a result of penetration of the evanescent electric field from the light in the inner core through the inner cladding (16) to the outer core. Control of the coupling length may be effected by suitable selection of the transducer structure parameters. At least one of the portions of the transducer is formed of an acousto-optically variable material whereby an acoustic field acting on the transducer causes a modulation of the coupled light so as to provide in the outer core (17) a modulated light signal suitable for detection by a receiver (21). Localized control of the parameters of the transducer may be effected to provide focusing of the coupled light. An electrical signal may be provided for controlling the coupling between the core portions.

Concentric fiber optical transducer

A transducer (14) including an optical fiber core (15) having a first refractive index profile, and an optical cladding (16) encircling the core and having a second refractive index profile different from that of the profile of the optical core. At least one of the core and cladding is formed of a photoresponsive material providing a variable difference between the refractive indices of the core and cladding as a function of a physical effect applied to the transducer. Light may be propagated through the core from a suitable light source (18) and the light which is lost from the core to the cladding may be detected by a suitable detector (22,23) providing an output signal corresponding to the force applied to the transducer. In one form, the detector receives light from the end (21) of the transducer, and in another form, the detector (23) receives light through the outer surface (24) of the transducer.

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Buffalo Grove, IL, United States of America

David W Stowe