Abstract: According to an exemplary embodiment of the present invention, an optical apparatus includes an optical filter array which comprises a plurality of optical filter elements, wherein at least one of the optical filter elements is adapted for tuning to two or more wavelengths. According to another exemplary embodiment of the present invention, an optical apparatus includes a monolithic optical filter array which further includes at least one tunable optical filter element. The optical apparatus also includes a tuning mechanism which tunes the tunable optical filter element to extract a signal of a particular wavelength from an optical signal which includes a plurality of wavelengths. According to another exemplary embodiment of the present invention, a method for selectively extracting optical signals of particular wavelengths includes providing a monolithic optical filter array which further includes at least one tunable optical filter element.

Abstract: In accordance with an exemplary embodiment of the present invention, an optical apparatus includes a glass monolithic structure including a plurality of optical filter elements, and the glass monolithic structure is not an optical fiber. In accordance with another exemplary embodiment of the present invention, an optical apparatus includes a glass monolithic structure which includes a plurality of optical filter elements. The optical apparatus further includes a device which selectively aligns an optical input and an optical output to one of said plurality of optical filter elements. In accordance with another exemplary embodiment of the present invention, a method of adding/dropping a particular frequency from an optical signal includes providing a glass monolithic structure which further includes a plurality of optical filter elements. The method further includes providing a device which selectively aligns an optical input and an optical output to one of the plurality of optical filters.

Abstract: An optical amplifier comprises: (i) an input port for providing optical signal to the amplifier; (ii) an output port for providing amplified optical signal out of the amplifier; (iii) at least two optical fibers, one optical fiber having positive dispersion D1 of greater than 10 ps/nm/km in a 1550 nm to 1620 nm wavelength range, the other fiber having negative dispersion D2 of less than −5 ps/nm/km in a 1550 nm to 1620 nm wavelength range, wherein the length of each of said optical fiber is chosen to provide the amplifier with a predetermined amount of dispersion.

Abstract: An amplifier system includes: (i) a distributed Raman fiber amplifier and; (ii) a discrete Raman fiber amplifier that includes dispersion compensated fiber. The discrete Raman fiber amplifier is operatively connected to the distributed Raman fiber amplifier and amplifies signals received from the distributed Raman fiber amplifier. In one embodiment, at least one source of pump signal is coupled to the distributed and to the discrete Raman fiber amplifier. The distributed Raman fiber amplifier and the discrete Raman fiber amplifier in this embodiment share optical pump power provided by the shared pump. In one embodiment of the present invention an Erbium doped fiber amplifier (EDFA) is operatively connected to a discrete Raman fiber amplifier and the Erbium dope fiber amplifier amplifies signals received from the discrete Raman fiber amplifier.

Abstract: According to an exemplary embodiment of the present invention, an optical apparatus includes an optical filter array which comprises a plurality of optical filter elements, wherein at least one of the optical filter elements is adapted for tuning to two or more wavelengths.

Abstract: According to an exemplary embodiment of the present invention, an optical apparatus includes an optical filter array which comprises a plurality of optical filter elements, wherein at least one of the optical filter elements is adapted for tuning to two or more wavelengths.

Abstract: In accordance with an exemplary embodiment of the present invention, an optical filter array includes a plurality of optical filter elements which are disposed in a glass monolithic structure, which is not an optical fiber.

Abstract: In accordance with an exemplary embodiment of the present invention, an optical apparatus includes a glass monolithic structure including a plurality of optical filter elements, and the glass monolithic structure is not an optical fiber.

Abstract: According to an exemplary embodiment of the present invention, an optical apparatus includes a monolithic optical filter array haiving a first optical filter element. The monolithic optical filter array also includes a second optical filter element proximate to the first optical filter element. The second optical filter element is detuned relative to the first optical filter element.

Abstract: According to an exemplary embodiment of the present invention, an optical apparatus includes a monolithic optical filter array having a first optical filter element. The monolithic optical filter array also includes a second optical filter element proximate to the first optical filter element. The second optical filter element is detuned relative to the first optical filter element.

Abstract: A method for upgrading bandwidth in a fiber optic system utilizing Raman amplification and having an initial band capacity provided by a plurality of pumps including the steps of identifying a fiber optic system to be upgraded, activating at least one new pump in the fiber optic system necessary to provide upgraded band capacity to the fiber optic system while retaining the initial band capacity provided by the plurality of pumps, and adjusting power of at least one pump of the fiber optic system to minimize gain ripple or signal output ripple.

Abstract: An optical amplifier comprises: (i) an input port for providing optical signal to the amplifier; (ii) an output port for providing amplified optical signal out of the amplifier; (iii) at least two optical fibers, one optical fiber having positive dispersion DI of greater than 10 ps/nm/km in a 1550 nm to 1620 nm wavelength range, the other fiber having negative dispersion D2 of less than −5 ps/nm/km in a 1550 nm to 1620 nm wavelength range, wherein the length of each of said optical fiber is chosen to provide the amplifier with a predetermined amount of dispersion.

Abstract: A method for upgrading bandwidth in a fiber optic system utilizing Raman amplification and having an initial band capacity provided by a plurality of pumps including the steps of identifying a fiber optic system to be upgraded, activating at least one new pump in the fiber optic system necessary to provide upgraded band capacity to the fiber optic system while retaining the initial band capacity provided by the plurality of pumps, and adjusting power of at least one pump of the fiber optic system to minimize gain ripple or signal output ripple.

Abstract: An amplifier system includes: (i) a distributed Raman fiber amplifier adapted to amplify C and L-band signals and; (ii) a discrete Raman fiber amplifier module that includes a C-band amplification stage and an L-band amplification stage. The discrete Raman fiber amplifier module is operatively connected to the distributed Raman fiber amplifier and amplifies signals received from the distributed Raman fiber amplifier. In one embodiment the distributed Raman fiber amplifier and the discrete Raman fiber amplifier share optical pump power provided by the shared pump.

Abstract: A symmetric, dispersion-managed fiber optic cable in accordance with the present invention includes a first and a second optical fiber. The first optical fiber is a conventional single mode fiber (SMF) type fiber and has a first effective area and a positive dispersion characteristic at a predetermined operating wavelength range. The first optical fiber is split into two segments each having substantially the same length. The second optical fiber has a second effective area and a negative dispersion characteristic at the operating wavelength range. Typically, second optical fiber is a DSF or an NZD fiber, both with negative dispersion and a small effective area. The second optical fiber is coupled between the two segments of the first fiber to create a fiber optic cable with an average total dispersion at the operating wavelength range which is substantially zero. The fiber optic cable may be incorporated into an optical fiber transmission system with an optical terminal and at least one repeater.

Abstract: A method is described for improving the compatibility of pigments and, optionally, stabilizers in the polyol-containing component of two- and three-component polyurethane systems. The method comprises(A) preparing a dispersion comprising at least one pigment in at least one glycol, and(B) blending said dispersion with the polyol component.In a preferred embodiment, the glycol of the dispersion is identical to the glycol used as the chain extender in the polyol component of the urethane system. The pigment dispersions also may contain at least one stabilizer for the urethane including heat stabilizers and ultraviolet light stabilizers. Compositions are described which comprise at least one pigment and at least one heat and/or ultraviolet light stabilizing compound dispersed in a glycol. Such dispersions exhibit improved compatibility with the polyol component thereby minimizing settling of the pigment resulting in a reduction in the clogging of filters used in the urethane reaction.