Kongsberg Seatex As

Multiwave Photonics Sa

Martin Ole Berendt

Paulo Tiago Guerreiro

Stefan Franz Grünsteidl

Rosa M Muniz

António B Lobo Ribeiro

José António Ribera Salcedo

Rosa M Muñiz

Irina Trifanov

João M Sousa

Miguel Alexandre Ramos De Melo

The present invention provides, in at least one embodiment, a system and method for power control of lasers. The system includes a device's control signal fed into a laser. The laser can be a master oscillator power amplifier (MOPA) fiber laser. The device includes an equivalent model circuit representing at least one parameter of the laser, such as the gain fiber inversion in the power amplifier. The device measures the power at the equivalent model circuit. Then, the device uses its feedback signal to control and/or adjust the output power control signal fed into the laser based on the measured power. By controlling the power fed into the laser, the laser can be operated at much lower frequencies while keeping the laser power within acceptable limits.

Real time equivalent model, device and apparatus for control of master oscillator power amplifier laser

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.

Adiabatic bend transitions for multimode fibers

The present invention provides an amplified spontaneous emission fiber optic source having high optical power (&#x3e;20 mW) and a spectral broadband emission (&#x3e;70 nm) centered near a wavelength of 1060 nm. In an embodiment of the invention, the fiber source comprises a combination of Yb-doped and Nd-doped silica fibers in a dual-pumping configuration. The Yb-doped optical fiber has a peak absorption coefficient of 350 dB/nm at 977 nm band, and the Nd-doped fiber used has a dopant concentration of 500 ppm-wt in a glass host of aluminum-germano-phospho-silicate. A combination of these two doped-fibers along with optical spectral filtering provides a broadband spectrum giving coherence length &#x3c;7 &#x3bc;m (in air), which is well suited for optical coherence imaging.

Broadband neodymium-ytterbium-silica doped amplified spontaneous emission optical fiber source by spectral filtered reinjected signals

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Árvore, Portugal

Martin Ole Berendt