Abstract: The invention involves providing a microstructured fiber having a core region, a cladding region, and one or more axially oriented elements (e.g., capillary air holes) in the cladding region. A portion of the microstructured fiber is then treated, e.g., by heating and stretching the fiber, such that at least one feature of the fiber microstructure is modified along the propagation direction, e.g., the outer diameter of the fiber gets smaller, the axially oriented elements get smaller, or the axially oriented elements collapse. The treatment is selected to provide a resultant fiber length that exhibits particular properties, e.g., mode contraction leading to soliton generation, or mode expansion. Advantageously, the overall fiber length is designed to readily couple to a standard transmission fiber, i.e., the core sizes at the ends of the length are similar to a standard fiber, which allows efficient coupling of light into the microstructured fiber length.

Abstract: The invention involves providing a microstructured fiber having a core region, a cladding region, and one or more axially oriented elements (e.g., capillary air holes) in the cladding region. A portion of the microstructured fiber is then treated, e.g., by heating and stretching the fiber, such that at least one feature of the fiber microstructure is modified along the propagation direction, e.g., the outer diameter of the fiber gets smaller, the axially oriented elements get smaller, or the axially oriented elements collapse. The treatment is selected to provide a resultant fiber length that exhibits particular properties, e.g., mode contraction leading to soliton generation, or mode expansion. Advantageously, the overall fiber length is designed to readily couple to a standard transmission fiber, i.e., the core sizes at the ends of the length are similar to a standard fiber, which allows efficient coupling of light into the microstructured fiber length.

Abstract: A packaging system includes a medium which transports energy in a first form away from a radiation point in a device to where the energy can be converted to a second form without damaging the device or effecting other devices. In certain embodiments, the medium can inhibit the propagation of energy in the second form. For example, in an optical coupling device, the medium includes a substrate adjacent to the radiation point which transports light energy away from the radiation point to a housing which converts the light energy into thermal energy away from the radiation point. In accordance with another aspect, the packaging system suspends at least a portion of the device, for example, to protect the device against a third form of energy. For example, in the optical coupling device, the medium includes an air gap which separates the radiation point from the substrate to suspend at least a portion of the device.

Abstract: A fiber amplifier, such as a rare-earth doped fiber amplifier, includes at least two separate sections of (doped) fiber, where residual pump power remaining in one stage (for example, the output stage) of the amplifier is coupled into, and re-used by, the remaining section of (doped) fiber. In particular, a second, longer section of fiber is directly pumped by an externally supplied pump signal and a first, shorter section of doped fiber uses residual pump power from the second section as a pump signal input.

Abstract: A packaging system includes a medium which transports energy in a first form away from a radiation point in a device to where the energy can be converted to a second form without damaging the device or effecting other devices. In certain embodiments, the medium can inhibit the propagation of energy in the second form. For example, in an optical coupling device, the medium includes a substrate adjacent to the radiation point which transports light energy away from the radiation point to a housing which converts the light energy into thermal energy away from the radiation point. In accordance with another aspect, the packaging system suspends at least a portion of the device, for example, to protect the device against a third form of energy. For example, in the optical coupling device, the medium includes an air gap which separates the radiation point from the substrate to suspend at least a portion of the device.

Abstract: The invention involves providing a microstructured fiber having a core region, a cladding region, and one or more axially oriented elements (e.g., capillary air holes) in the cladding region. A portion of the microstructured fiber is then treated, e.g., by heating and stretching the fiber, such that at least one feature of the fiber microstructure is modified along the propagation direction, e.g., the outer diameter of the fiber gets smaller, the axially oriented elements get smaller, or the axially oriented elements collapse. The treatment is selected to provide a resultant fiber length that exhibits particular properties, e.g., mode contraction leading to soliton generation, or mode expansion. Advantageously, the overall fiber length is designed to readily couple to a standard transmission fiber, i.e., the core sizes at the ends of the length are similar to a standard fiber, which allows efficient coupling of light into the microstructured fiber length.

Abstract: The disclosed fiber Raman device comprises means for coupling pump radiation of a first wavelength &lgr;1 and a second wavelength &lgr;2 into a length of silica-based fiber, with &lgr;1 being different from &lgr;2, and with both of &lgr;1 and &lgr;2 being less than an output radiation &lgr;0 of the fiber Raman device. The Raman device further comprises at least a first and a second wavelength-selective element disposed to provide one or more optical cavities for Raman shifting of light in the fiber. At least one of the optical cavities is selected such that at least one of &lgr;1 and &lgr;2 is off resonance. Exemplarily, the Raman device is a topologically linear or circular Raman laser or amplifier, and the wavelength selective element is a fiber Bragg grating or a WDM. The Raman device is advantageously used in an optical fiber communication system.

Abstract: A method and article for monitoring and controlling power drift in the output of a diode array is described. The diode array is used, for example, as a light pump for a fiber laser. In one embodiment, an improved fiber laser includes the light pump, which launches light into a laser cavity. The fiber laser further includes a sampler operable to receive at least a portion of the light before it is launched into the laser cavity. The sampled portion represents a known fraction of the total light signal generated by the light pump. In some embodiments, the sampled light is directed, via the sampler, to a photodetector. The photodetector converts the sampled light into a first electrical signal and delivers it to a processor. The processor is operable to compare the electrical signal with a set-point signal representative of a desired power output of the sampled portion of the launched light.

Abstract: Applicants have discovered that exposing optical fiber to an electrical arc produces a perturbation in its refractive index and that gratings can be made by exposing fiber to arcs at a series of locations along its length. In a first variation of the process, the fiber is exposed under tension to a high current arc (>15 mA) for a prolonged period of time (>2 s). Using this method, long period gratings can be successfully fabricated from fiber without the use of special dopants. In a second variation, the fiber is doped and the tension is reduced. The resulting grating is optically weaker but mechanically stronger. A third variation uses hydrogen-sensitized fibers and reduced currents and times. The resulting grating is optically and mechanically strong.