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Denne Ph.D. afhandling omhandler fremstilling af fiber koblere til høj-effekts fiber lasere og forstærkere. Hovedfokus i afhandlingen ligger på en videreudvikling af pumpe koblere til air-clad fotoniske krystal fibre (PCF), og implementeringen af en signal gennemførsel i disse koblere. En pumpe/signal kobler muliggør fremstilling af fiber baserede splidsede fiber forstærkersystemer baseret pa PCF teknologien. Forstærker systemer hvis interface udelukkende bestar af standard multi-mode og single-mode fibre, er nemme at anvende fordi fuldt splidsede systemer kan konstrueres uden brug af linse optik. Pumpe/signal koblere blev i projektet fremstillet i to versioner; en med en 12 m mode field diameter (MFD) signal gennemførsel og en med en 15 m MFD gennemførsel.En signal kobler, der kombinerer lyset fra flere single-mode (SM) fiber lasere over i en enkelt multi-mode (MM) fiber blev også fremstillet. Komponenten er baseret pa en taperet fiber bundt fremgangsmåde og blev testet op til 2.5 kW kombineret udgangs effekt.To komponenter til astrofotonik blev også fremstillet. Den første var et fiber bundt, designet til at blive placeret i fokal planet af et teleskop. Ved at måle det spektrale indhold i de enkelte fibre, opnås en mere detaljeret observation af store astronomiske objekter. Den anden komponent var videreudvikling af en MM til SM kobler. Disse komponenter blev udviklet til brug indenfor astrofotonik, hvor koblingen af MM stjernelys til en samling af SM fibre muliggør filtrering med avancerede Bragg gitre. The work presented in this Ph.D. thesis focuses on the fabrication of fused combiners for high-power fiber lasers and amplifiers. The main focus of the Ph.D. project was to further develop the fused pump combiners for airclad photonic crystal bers (PCFs), and implement a signal feed-through in these combiners. Such a pump/signal combiner enables the fabrication of all spliced fiber amplifier systems based on the PCFs technology. Amplifier systems interfaced only by standard multi-mode (MM) and single-mode (SM) fibers are easy to use, since all-spliced systems can be made and bulk optics are avoided. Pump/signal combiners were realized in two versions; one with a 12 m mode field diameter (MFD) signal feed-through and one with a 15 m MFD feed-through.A signal combiner for combining the SM output from multiple fiber lasers into a single MM fiber was also realized. The component was based on a tapered fiber bundle approach and was tested up to 2.5 kW of combined output power.Two components for the field of astrophotonics have also been developed. The first was a fused fiber bundle, designed to be placed in the focal plane of a telescope. By measuring the spectral content out of the individual fibers in the bundle, more detailed observations of large astronomical objects can be achieved. The second component was a further development of the MM to SM converters or photonic lanterns. These components were developed for the field of astrophotonics, where the transformation of MM starlight into an ensemble of SM fibers enables filtering with advancedfi ber Bragg gratings (FBGs). |
