Abstract: A system including an erbium doped fiber amplifier (EDFA), comprising a length of erbium doped fiber having a first end and a second end, an isolator wavelength division multiplexer (IWDM) comprising an output optically connected at an optical connection with the first end of the erbium doped fiber, wherein the optical connection with the first end of the erbium doped fiber is continuous between the IWDM and the first end of the erbium doped fiber, and an isolator comprising an input optically connected at an optical connection with the second end of the erbium doped fiber.

Abstract: In part, the disclosure relates to an apparatus that may include a first lens; wherein the first lens is enabled to be optically connected to an optical fiber; an isolator core optically coupled to the first lens; a second lens optically coupled to the isolator core; wherein the second lens is enabled to be optically connected to another optical fiber; wherein the isolator core is enabled to allow optical power from the first lens to propagate through the isolator core; wherein the isolator core is enabled to block optical power from the second lens from propagating through the isolator core; a first optical filter optically coupled to the first lens; and a second optical filter optically coupled to the second lens; wherein the second optical filter is enabled to reflect a first frequency; wherein the isolator core is enabled to absorb a remaining portion of the first frequency.

Abstract: A system including an erbium doped fiber amplifier (EDFA), comprising a length of erbium doped fiber having a first end and a second end, an isolator wavelength division multiplexer (IWDM) comprising an output optically connected at an optical connection with the first end of the erbium doped fiber, wherein the optical connection with the first end of the erbium doped fiber is continuous between the IWDM and the first end of the erbium doped fiber, and an isolator comprising an input optically connected at an optical connection with the second end of the erbium doped fiber.

Abstract: A fiber optic device for changing direction along a fiber optic path is provided. A first optical fiber having a first end portion, and a second optical fiber having a second end portion are joined at a fusion splice. A miniature bend is formed in the region of the fusion splice. The device is particularly useful for routing optical fibers in the field. A method of forming such a miniature bend in a fusion splice region between two optical fibers is also provided.

Abstract: An optical fiber Mach Zehnder Interferometer includes a first and second elongate optical fiber having a core and a cladding, first and second couplers wherein the cladding of the first optical fiber is coupled to the cladding of the second optical fiber. The first optical fiber includes a first elongate interfering arm where the first optical fiber extends between the first and second couplers. The first interfering arm includes a miniature bend formed therein. The second optical fiber includes a second elongate interfering arm extending between the first and second couplers and may also include a miniature bend formed therein. The miniature bends are contemplated to be either packed or unpackaged. The fibers may exhibit different coefficients of thermal expansion to maintain the path length differences of the interfering arms.

Abstract: A graded index fiber formed of a plurality of fused graded index fibers is provided. Each fiber is formed from a preform comprising a plurality of fused low index rods with at least one high index rod arranged in a pre-determined pattern which have been drawn and fused. An array may be made utilizing such fibers, with each fiber having a center located at a specified position. A method of forming the GRIN fibers and the GRIN fiber array is also provided.

Abstract: An optical interconnection member for interconnecting at least one optical fiber with a data processing unit. The interconnection member comprises an optical, electrical conversion device, an optical transformation array and an adapter. The conversion device is mounted in operable alignment with the data processing unit and the adapter is adapted to receive the connector. The optical transformation array defines an optical transmission medium between non-parallel input and output surfaces whereby the connector and the data processing unit can be interconnected in a non-perpendicular manner.

Abstract: The present invention is a fused/taper fiber optic coupler and related methodologies for a fuse/taper fiber optic coupler with an FBG that does not excite cladding modes and maintains the coupling regions of the fibers in the proper relationship to one another without a complex and expensive process. Aspects of the fused/taper fiber optic coupler include the use of optical fibers with a three layer structure. The optical fibers include a photosensitive core layer, a photosensitive inner cladding layer, and a photo-insensitive outer cladding layer. Coupling regions are formed in each optical fiber by removing the outer cladding layer and the coupling regions in each optical fiber are then helically intertwined. The intertwined coupling regions are then heated and drawn forming a tapered area in which an FBG may be written.

Abstract: A passive temperature compensating package for a fiber Bragg grating device in which the fiber Bragg grating is written to the fiber prior to the temperature compensation being set. As the temperature of the package increases the fiber is de-stressed and at the desired proper resonant frequency, the fiber containing the fiber Bragg grating is secured to the package. As the package cools and expands, the fiber is pre-stressed and maintains the desired resonant frequency.

Abstract: An asymmetric optical fiber Mach-Zehnder interferometer has first and second optical fibers connected at a first coupling region and a second coupling region. The first and second optical fibers form two interfering arms between the first and second coupling regions. To form the asymmetry, the propagation constant in a portion of the first optical fiber in one of the coupling regions differs from the propagation constant in a portion of the second optical fiber in that coupling region. The asymmetric structure provides 30 dB isolation over a greater wavelength span.

Abstract: An optical fiber add/drop filter includes a first and second elongate photosensitive optical fiber, each optical fiber having opposed first and second ends and including a core and a cladding. The cladding of the first optical fiber is optically coupled to the cladding of the second optical fiber at a coupler. A first fiber Bragg grating is etched into a second end of the first fiber for converting light propagating in a first direction through either of the core of cladding of the first fiber into light propagating in an opposite direction through the other of said core and cladding of said second fiber. A second fiber Bragg grating is etched into a first end of the second fiber for converting light propagating in a first direction either of the core or cladding of the second fiber into light propagating in an opposite direction through the other of the core and cladding of the second fiber. The first and second fiber Bragg gratings are located to opposite sides of the coupler.

Abstract: A varied ratio coupler, and a method of forming the same, constructed and arranged, in a unitary structure, to cause optical power in an input optical fiber to couple asymmetrically to at least two output optical fibers in a manner establishing different insertion losses between the input fiber and at least two output optical fibers. The coupler includes a central fiber surrounded by a close-packed ring of fibers. In certain preferred embodiments, the coupler has a bend that lies in a preselected plane and has a radius of curvature that is selected to provide the above difference in the insertion losses.

Abstract: In one aspect, the invention concerns fused fiber optic couplers of the type formed from fibers of transparent substance each having a circular cross-section of preselected diameter. The fibers include a central fiber and at least one ring of closely packed surrounding fibers with at least some of the fibers being optical fibers that have a core and a surrounding cladding. The coupler is formed by the processes of providing the fibers, assembling them in a close-packed relationship, and heating and drawing the assembly of fibers in the close-packed region.We have discovered that the steps involved in forming such a coupler, introduce slight size variations that can seriously affect the performance of the coupler, and that these slight variations can be accommodated by slight, controlled, under-sizing of one or more of the surrounding fibers or over-sizing of the central fiber.