Abstract: The present invention provides a method and resulting device for producing a low-loss spectrally periodic all fiber filter by providing a multi-mode fiber capable of propagating an LP01 mode and an LP02 mode at wavelengths of interest and providing a single-mode fiber capable of propagating a fundamental mode at the wavelengths of interest and splicing a selected length of the multi-mode fiber between lengths of the single-mode fiber, where the properties of the multi-mode fiber and the single-mode fiber are related such that the optical field distribution resulting from the coherent superposition of the optical field of the LP01 mode and the optical field of the LP02 mode in the multi-mode fiber is sufficiently similar to the optical field distribution of the fundamental mode in the single-mode fiber at the wavelengths of interest, such that transmission across the two splices taken together at the wavelengths of interests is at least 70%, desirably at least 80% and most desirably at least 90%, and the extin

Abstract: An optical 2R regenerator includes a decreasing dispersion optical fiber (DDF), or a Raman pump, or both.

Abstract: A high power laser system comprising: a master laser; and a primary slave laser oscillator including a cavity comprising a rare earth doped fiber, said primary slave laser oscillator being actively injection-locked to said master laser, wherein said cavity provides an output exceeding 1 W of optical power.

Abstract: A pulsed cascaded Raman laser (10) includes a pulsed light source (102) for generating a pulsed light (104) having an optical spectrum centered at a source wavelength. A non-linear Raman conversion fiber (106) is coupled to the pulsed light source (102). The pulsed light (104) traverses the nonlinear Raman conversion fiber (106) and the source power at the source wavelength is converted to a power output of an output signal (108) having an output wavelength longer than the source wavelength by a cascaded Stimulated Raman Scattering process, such that most of the source power is converted to the power of the last Stokes order in a single pass through the non-linear Raman conversion fiber (106).

Abstract: An all-optical method of regenerating an optical return-to-zero format pulse signal of a first wavelength starts by introducing the input signal into a first end of a non-linear optical fiber to obtain a modified signal comprising pulses broadened in the wavelength domain. When this modified signal emerges from the second end of said non-linear optical fiber, a bandwidth slice is selected that is centered on a second wavelength so spaced from the first wavelength that its intensity is substantially unresponsive to weak pulses in the signal and relatively insensitive to intensity for other pulses. This slice is returned to the same non-linear optical fiber at its second end so that a further modified signal comprising pulses broadened in the wavelength domain will emerge from its first end. From this further modified signal a bandwidth slice centered on the first wavelength is selected as regenerated output. Regenerators operating in this way are also disclosed.

Abstract: A dispersion correction optical fiber includes a segmented core having a central core segment, a moat segment and, preferably, a ring segment. The refractive index profile is selected to provide a total dispersion minimum which is located within an operating wavelength band of the fiber. Most preferably, the dispersion value at the minimum is more negative than ?400 ps/nm/km and greater than ?1200 ps/nm/km at 1550 nm. Optical transmission systems including the present invention dispersion correction optical fiber optically coupled to various transmission fibers and dispersion compensating fibers are also disclosed, as is a method of operating the dispersion correction fiber wherein the minimum is located within the desired operating wavelength band.

Abstract: An optically-pumped mode-locked fiber ring laser for optical clock recovery of multiple wavelength division multiplexed optical signals actively mode-locks a plurality of outputs of the laser as a plurality of recovered clocks for a plurality of the multiple wavelength division multiplexed optical signals. The laser cavity has a cavity length corresponding to an integer multiple of bit periods of at least one of the multiplexed optical signals for receiving a pre-amplified version of the plurality of wavelength division multiplexed optical signals to provide gain modulation through a phase-insensitive parametric amplification and recirculating a proportion of the output from the laser cavity back through the laser cavity for spatially mode-locking the output of the laser cavity as a recovered clock.