Abstract: Guided adiabatic bend transitions for multimode fibers are presented to preserve the power of guided light in the fundamental mode while guiding from one level of curvature to another for improved operation of mode filters and fiber amplifiers. A method is provided to find the guidance path. Implementations of these transducers include modal power back converters, and guidance paths into and out of higher order mode filtering devices which work on bending. A spiral structure is shown to incorporate adiabatic bends for a forward-pumped fiber amplifier.

Abstract: Guided adiabatic bend transitions for multimode fibers are presented to preserve the power of guided light in the fundamental mode while guiding from one level of curvature to another for improved operation of mode filters and fiber amplifiers. A method is provided to find the guidance path. Implementations of these transducers include modal power back converters, and guidance paths into and out of higher order mode filtering devices which work on bending. A spiral structure is shown to incorporate adiabatic bends for a forward-pumped fiber amplifier.

Abstract: A fiber-optic laser source capable of emitting multiple useful wavelengths at the same time, including multiple ITU grid wavelengths, is disclosed. The laser preferably comprises a diode-pumped rare-earth doped fiber amplifier as gain medium, a periodic filter to define a first set of possible lasing wavelengths corresponding to ITU grid lasing wavelengths, and a resonant filter for defining a subset of the first set of wavelengths. The arrangement is enclosed in a ring resonator. The ring resonator may be made, in part or in total, with polarization-maintaining optical fiber. The resonator may also comprise in-line optical isolators to ensure unidirectional operation and to eliminate undesired reflections. A gain-flattening filter may also be included within the resonator depending on the desired output characteristics of the laser. The laser may be designed to operate in a set of single cavity longitudinal modes.

Abstract: A fiber-optic laser source capable of emitting one useful wavelength at a given time, electrically step-tunable to the ITU grid wavelengths, is disclosed. The laser preferably comprises a diode-pumped rare-earth doped fiber amplifier as gain medium, a periodic filter to define ITU grid lasing wavelengths, and a tunable filter electrically step tunable to any wavelength defined by the periodic filter. The arrangement is enclosed in a ring single mode optical fiber resonator. The ring resonator may be made, in part or in total, with polarization-maintaining optical fiber. The resonator also comprises in-line optical isolators to ensure unidirectional operation and to eliminate undesired reflections. A polarization controller and polarizer device and a gain-flattening filter may also be included within the resonator depending on the desired output characteristics of the laser. The laser may be designed to operate in single cavity longitudinal mode.

Abstract: A fiber-optic laser source capable of emitting one useful wavelength at a given time, electrically step-tunable to the ITU grid wavelengths, is disclosed. The laser preferably comprises a diode-pumped rare-earth doped fiber amplifier as gain medium, a periodic filter to define ITU grid lasing wavelengths, and a tunable filter electrically step tunable to any wavelength defined by the periodic filter. The arrangement is enclosed in a ring single mode optical fiber resonator. The ring resonator may be made, in part or in total, with polarization-maintaining optical fiber. The resonator also comprises in-line optical isolators to ensure unidirectional operation and to eliminate undesired reflections. A polarization controller and polarizer device and a gain-flattening filter may also be included within the resonator depending on the desired output characteristics of the laser. The laser may be designed to operate in single cavity longitudinal mode.