Abstract: An optical probe suitable for medical or dental tomography is switchable between a rotating and non-rotating mode to control interference between source signals and data signals. The probe is suitably constructed in an in-line configuration and uses Faraday rotators which rotate polarization in the same direction in a rotating mode and rotate polarization in opposite directions in a non-rotating mode.

Abstract: An optical probe suitable for medical or dental tomography is switchable between a rotating and non-rotating mode to control interference between source signals and data signals. The probe is suitably constructed in an in-line configuration and uses Faraday rotators which rotate polarization in the same direction in a rotating mode and rotate polarization in opposite directions in a non-rotating mode.

Abstract: Apparatus and methodology for the low coupling of optical fibers in high power applications. An end of a single mode optical fiber, or a polarization maintaining fiber, is cut and spliced to a relatively short segment of an index matched multi-mode fiber or an optical fiber without cladding (air cladded) having approximately similar diameter as the single mode fiber which in turn is coupled to the external device. The free end of the multi-mode fiber may be cleaved, polished and have an anti-reflection applied to it. The beam emitted by the small core of the single mode optical fiber expands into the larger core of the multi-mode fiber providing low loss high power coupling of the optical fiber to the external device.

Abstract: A compact inline fiber optic polarization splitter/combiner for use in fiber optic communications. The splitter/combiner uses two birefringent wedges aligned with their optical axis at 90° from each other and their bases disposed oppositely to each other. One lens is used at the input to couple light from the input fiber. A single output lens is used to couple light into two adjacent polarization maintaining fibers. When used as a combiner a beam of a first linear polarization state from one input fiber is combined with a beam of second linear polarization state from a second input fiber into a third output fiber carrying both beams. The splitter/combiner also provides for the ready alignment of the input and output beams further saving cost and complexity.

Abstract: Optical polarization maintaining couplers which may be used as a splitter(divider) or a combiner (multiplexer). The couplers utilize a series of partial reflectors disposed in the lightpath between the input fiber and the output fibers. The couplers may be used to form 1 or 2 by N devices with the input and output fibers disposed at right angles to each other forming a compact, efficient polarization maintaining optical coupler.

Abstract: Optical isolators for use in fiber optic networks utilizing a birefringent wedge set with a Faraday rotator disposed between the birefringent wedges. In a first embodiment a polarization maintaining optical isolator is disclosed which will maintain the polarization of the light which passes through it in a forward direction and block light in the reverse direction. In a second embodiment a single polarization optical isolator is disclosed which will pass only a single linear polarization of the light in a forward direction and block any light in the reverse direction.

Abstract: An inline fiber optic polarization combiner/divider is proposed for use in fiber optic communications. It utilizes a polarizing beam splitting cube (PBSC) or a birefringent displacer located between a pair of collimating lenses. A reflecting film (either external or directly applied to one of the faces of the PBSC or birefringent displacer) is used to completely reflect one of the two polarizations and is positioned such that the optical path length between the lens and the reflecting film is equal to one focal length in order to accomplish an optical path where the input and output optical fibers are in-line with the package.

Abstract: Polarization maintaining optical circulators for fiber optic applications. A first embodiment uses birefringent wedges and Faraday rotators in an inline configuration. The second embodiment utilizes a polarizing beam splitting cube and Faraday rotators which results in a design with the fibers being at either 90° or 180° with respect to each other, all in the same plane. A third embodiment makes use of a polarizing beam splitter cube and Faraday rotators with a reflector on one or both of the sides of the beam splitting cube which provides an device.

Abstract: An inline fiber optic polarization combiner/divider is proposed for use in fiber optic communications. It utilizes a polarizing beam splitting cube (PBSC) or a birefringent displacer located between a pair of collimating lenses. A reflecting film (either external or directly applied to one of the faces of the PBSC or birefringent displacer) is used to completely reflect one of the two polarizations and is positioned such that the optical path length between the lens and the reflecting film is equal to one focal length in order to accomplish an optical path where the input and output optical fibers are in-line with the package.

Abstract: A FOG system with a high polarization extinction ratio includes an integrated optic circuit (IOC) having a waveguide array fabricated by a proton exchange (PE) process, the IOC being operatively connected for providing single mode, single polarization filtering of incident light guided from the FOG light source to the sensing loop and of the interference signal guided from the sensing loop to the detector.

Abstract: A single polarization active IO device includes a crystalline material substrate having an IO circuit array comprising an optical waveguide array disposed on a major surface of the substrate by a two step proton exchange (TSPE) process, and including an electrode array disposed on the major surface in juxtaposed relation with the waveguide array to provide one or more active IO regions thereon.

Abstract: An optical power star coupler includes a LiNbO.sub.3 or LiTaO.sub.3 substrate having a major surface for receiving a circuit array of one or more surface for splitters disposed thereon by a two step proton exchange (TSPE) process, in a geometric pattern to provide an N.times.M star coupler having high polarization extinction, uniform splitting ratio, and low loss.

Abstract: A single-mode integrated optical star coupler employing weighted directional coupling between pairs of non-parallel waveguides formed on a substrate. Light launched into an input waveguide is split into desired, and usually equal-power proportions among a plurality of output waveguides, without the use of conventional Y-section branches and with a minimum of waveguide bends. At each non-parallel coupling point, light in a first waveguide is coupled, to a predetermined degree, into a second waveguide with one end in a close, non-parallel relationship with the first waveguide. In one embodiment, the output waveguides are all coupled to the input waveguide in this manner. In other embodiments, the input waveguide power is first split between two principal output waveguides, and other output waveguides are coupled to the principal output waveguides.