ausblenden:
Schlagwörter:
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Zusammenfassung:
At this time, the world is witnessing the development of projects whose aim is to detect gravitational waves which so far have not been observed directly. The large-scale interferometric detector constitutes the most promising design especially in view of the vast choice of possible technological improvements which can be implemented in the next generation of detectors. Nevertheless, the prospect of success does not exclusively depend on the technology of the detectors. In particular, theorists have to provide accurate predictions of the form of gravitational waves for many different sources and they also have to optimize data analysis under the condition of limited computational power. The mentioned subtasks should not be considered separately.
The first part of this thesis comprises a theoretical investigation of a data analysis problem of the Big Bang Observer. For the success of this potential future mission – the detection of the cosmic gravitational-wave background – one has to guarantee that the dominant signals from other sources are subtractable from the data stream once it has been recorded. Subtraction of a signal requires an accurate estimation of its parameter values which determine an otherwise predictable form of the wave. The latter task is crucially hampered by confusion noise emerging from a very large number of other yet unsubtracted signals. However, the results indicate that a subtraction of all dominant signals – i.e. all binary stars of the universe with a certain orbital frequency – is feasible at least for the standard design of the detector. In the following chapters of this thesis, the theoretical means to investigate the optical properties of interferometric detectors are developed and applied. Apart from the necessity of a quantum mechanical explanation of the existence of minimal optical fluctuations, the focus lies on the classical properties and transformations of the optical systems. Primarily, the linear relations between input and output fields are calculated for the relevant Michelson topologies. The respective relations of the GEO600 detector are presented in all detail taking explicitly into account the active radiation pressure. In this thesis it is presumed that the final photo detection is sensitive to the phase of the light. Hence, in most cases the bivariate distribution of the field’s quadrature phases is considered. In addition, this formalism allows in a simple way to include correlations between the amplitude and the phase of the field. Fields with minimal fluctuations which exhibit amplitude-phase correlations assume a so-called squeezed state which may contribute to an improvement of the sensitivity of the detectors. On the one hand, optical parametric amplifiers may provide squeezed states externally. On the other hand, they can be generated ponderomotively or by Kerr media inside the detector. In the end, the investigations are brought into a more general context comparing the performance of position meters with that of more innovative topologies like for example the optical lever or the optical speed meter.
