@article{2012-thau,
	Abstract = {<p>
	The demand for fiber cavities for studying light matter interaction increased in the recent years. The ablation setup in Paris is used as a basic tool for fabricating fiber mirrors by ablating material on a fiber end facet with a CO2 laser. In this work we improved the controllability and the efficiency of the setup. A better quality of the CO2 laser beam was achieved by the minimisation of the astigmatism caused be the dichroic mirror. This enables the adjustment of a certain beam radius by moving the fiber end facet along the beam direction. Based on the experiences in Paris, we built up an improved ablation setup in Bonn. The dichroic mirror and the microscope are substituted by a new alignment method of the fiber end facet. A 1550nm laser is overlapped with the CO2 laser beam and coupled into the fiber. By the amount of light coupled into the fiber, the position of the fiber is determined. As a new approch, a Michelson profilometer is implemented into the setup to determine the structure profiles on the fiber end facet. All electrical components in the ablation setup are controlled centrally with a MBED microcontroller which will enable an automated alignment of the fiber and ablation process in the future. In a further experiment, the properties of a fiber cavity are investigated in Paris. Elliptically polarized light at a wavelength of 900nm is coupled into the cavity and from the transmission signal as well as the camera pictures, the free spectral range, the finesse and the spectral width is determined. From this, the reflectivity of the mirrors, the mode waist and the cavity field decay rate are roughly estimated. Especially the birefringence of the mirror coating was also investigated in this measurement and is observed as a resonance splitting in the transmission signal.</p>},
	Author = {Thau, N.},
	Journal = {},
	Pages = {},
	Title = {{Optical fiber cavities}},
	Volume = {},
	Year = {2012}
}