Abstract: A pulsed laser light source is provided. A continuous light beam is first generated by a CW laser source such as a laser diode, a superfluorescent source or a CW solid state laser. The continuous light beam is then modulated by a first modulator, and further shaped by a second modulator at least in partial synchronization with the first. The first and second modulators are preferably each followed by a gain medium for signal amplification.

Abstract: A process for eradicating moss and liverwort which includes applying sodium percarbonate; and irrigating the moss. In some cases the process includes applying lime to control the pH of the moss and thereby constrain development of additional moss and said sodium percarbonate is a solid material.

Abstract: An apparatus for generating variable DGD is particularly for use in a PMD compensator. The apparatus has first, second and third birefringent elements arranged in order between the input and output of the compensator and having first, second and third differential group delays (DGDs) in the ratio 1:2:1. The orientation of the PSPs of the signal in each element relatively to the principal axes of the element is controlled, such that a change in orientation between the first and second elements is equal and opposite to a change in orientation between the second and third elements. This arrangement provides symmetrical relative rotations of the signal PSPs and principal axes about the central birefringent element. In combination with the 1:2:1 ratio, it can be shown that compensation of any first order PMD can be achieved without the compensator introducing additional second order PMD. The required level of first order PMD compensation is selected by controlling the amount of the orientation changes.

Abstract: An additive for animal feed which includes sodium percarbonate. The sodium percarbonate may be in solid form. The invention also includes an animal feed that includes nutritional material and sodium percarbonate. In various forms of the invention the sodium percarbonate constitutes at least 1 percent or at least 2 percent by weight of the entire weight of the animal feed. The animal feed may be in pellet form and the sodium percarbonate may be present in substantially all of the pellets. In some embodiments of the invention the sodium percarbonate constitutes less than 8 percent by weight of the entire weight of said animal feed. Some embodiments of the animal feed in accordance with a present invention do not include any mammalian animal proteins.

Abstract: A process for controlling a wide variety of simple celled pests by applications of various formulations using sodium peroxyhydrate as a principal active ingredient. Some forms of the pesticide further include at least one other less reactive material which may be selected from the group consisting of lime (calcium oxide), gypsum, clay calcium nitrate, urea, calcium nitrate tetrahydrate, ammonium nitrate, monocalcium phosphate, dicalcium phosphate, ammonium phosphate, a fertilizer, a form phosphate, and epsom salt. In some embodiments of the invention the pesticide includes a material selected to control the pH at the area of application and thereby constrain the development of microorganisms. The invention also includes the process for controlling microorganisms on turf which comprises applying sodium percarbonate and irrigating the turf. The sodium percarbonate may be utilized in either a solid form or may be in solution.

Abstract: An improved method is provided for reducing four-wave mixing induced degradation in an optical data signal traversing an optical transport network that uses Raman amplifiers. The method includes: introducing at least two Raman amplifiers into the optical transport network, each Raman amplifier having a laser source, and synchronously modulating the laser sources of the Raman amplifiers, thereby reducing four-wave mixing in the optical data signal. Modulation of the laser sources is performed at such a rate that crosstalk from the modulation to the optical data signals experiencing the Raman gain is minimized.

Abstract: Generation of variable differential group delay An apparatus for generating variable DGD is particularly for use in a PMD compensator. The apparatus has first, second and third birefringent elements arranged in order between the input and output of the compensator and having first, second and third differential group delays (DGDs) in the ratio 1:2:1. The orientation of the PSPs of the signal in each element relatively to the principal axes of the element is controlled, such that a change in orientation between the first and second elements is equal and opposite to a change in orientation between the second and third elements. This arrangement provides symmetrical relative rotations of the signal PSPs and principal axes about the central birefringent element. In combination with the 1:2:1 ratio, it can be shown that compensation of any first order PMD can be achieved without the compensator introducing additional second order PMD.

Abstract: An improved method is provided for reducing four-wave mixing induced degradation in an optical data signal traversing an optical transport network that uses Raman amplifiers. The method includes: introducing at least two Raman amplifiers into the optical transport network, each Raman amplifier having a laser source, and synchronously modulating the laser sources of the Raman amplifiers, thereby reducing four-wave mixing in the optical data signal. Modulation of the laser sources is performed at such a rate that crosstalk from the modulation to the optical data signals experiencing the Raman gain is minimized.

Abstract: An optical fiber pumping apparatus for use with a double-cladding fiber in an optical amplifier or laser configuration comprises a plurality of laser diodes used as pump sources disposed in a spatial configuration for radiating pump energy along an optical axis through a surrounding generally annular area, leaving an available middle area. The apparatus further comprises an optical coupling device having an optical input portion generally aligned with the optical axis to collect the pump energy and having an optical output portion aligned with the pumping input portion for transferring the pump energy to the inner cladding surrounding the doped core of the fiber. The apparatus exhibits high pump power rating and allows efficient input signal coupling in optical fiber amplifier applications. According to the different preferred embodiments, the apparatus can act either simultaneously or independently as a pump combiner, multiple pump injector, signal coupler or pump/signal multiplexer/demultiplexer.

Abstract: A laser to produce pulses of light having predetermined spectral shapes, comprising a waveguide, an optical pump source, a gain medium to produce seed radiation, and a modulator and an array of Bragg gratings to modify the properties of the seed radiation. Once generated by the gain medium, the seed radiation propagates in the waveguide where it is first pulsed by the modulator. The resulting pulses are then selectively reflected by the Bragg gratings, which separates different spectral components of the reflected beam. This reflected beam then travels back to the modulator, which is timed to let only the desired spectral components go through. In this manner the laser is self-seeded and allows spectrum and wavelength selection from pulse to pulse.

Abstract: An optical time domain reflectometer suitable for determining its front panel insertion loss comprises a four-port coupler having first and second ports connected to a light source and an optical detector, respectively, and third and fourth ports connected to a front panel connector and a reference reflector, respectively. In use, a fiber-under-test is connected to the front panel connector. The coupler splits light from the light source between the front panel connector and the reference reflector and couples light returning from the front panel connector and reflector to the detector. The optical path between the front panel connector and the coupler is longer than the optical path between the reference reflector and the coupler by such a distance that a Fresnel reflection pulse from the reference reflector, produced by a pulse emitted by the light source, will be received by the detector before a corresponding reflection pulse returned from the front panel connector.