Showing papers by "Karsten Danzmann published in 1997"
TL;DR: The European Space Agency has selected LISA, a gravitational wave observatory, as a cornerstone mission in its future science program Horizons 2000 as mentioned in this paper, which will enable the observation of lowfrequency gravitational waves in a frequency range from 10−4 to 10−1 Hz which is totally inaccessible to ground-based experiments.
Abstract: The European Space Agency has selected LISA, a gravitational wave observatory, as a cornerstone mission in its future science program Horizons 2000. This observatory will complement the development of ground-based gravitational wave detectors currently under construction. A spaceborne detector will enable the observation of low-frequency gravitational waves in a frequency range from 10−4 to 10−1 Hz which is totally inaccessible to groundbased experiments. This frequency range is unique in that it is expected to contain signals from massive black holes, galactive binary stars, as well as the most violent events in the Universe. LISA will attain this low-frequency sensitivity by employing laser interferometric distance measurements over a very long baseline of 5 × 106 km. Three of these baselines form an equilateral triangle with spacecraft at each vertex. The cluster of spacecraft is in an Earth-like orbit around the Sun trailing the Earth by 20◦. The spacecraft contain infrared light-emitting Nd:YAG lasers and freely floating test masses made from a special platinum–gold alloy with vanishing magnetic susceptibility. The spacecraft are being kept centred on their test masses by using drag-free technology and field-emission electric propulsion, thus letting the test masses follow purely inertial orbits. PACS numbers: 0480N, 9555Y
153 citations
TL;DR: In this paper, the authors proposed a new concept to realize optical cavities with large buildup but broadband response (white-light cavities) using atomic phase coherence, which is useful to improve the bandwidth and sensitivity of future generations of laser interferometric gravitational wave detectors.
124 citations
TL;DR: In this article, the authors presented an optical resonator with modified properties due to a nonabsorbing highly dispersive medium, which is created with an additional pump field in an atomic beam using the effect of coherent population trapping.
Abstract: We present an optical resonator with modified properties due to a nonabsorbing highly dispersive medium. The steep nonabsorbing dispersion is created with an additional pump field in an atomic beam using the effect of coherent population trapping. The linewidth of such a resonator depends on the slope of the dispersion line, which in turn depends on the atomic density and the intensity of pump and probe field. In the experiments presented here, the cavity linewidth is reduced by a factor of more than 50 relative to the linewidth of the empty resonator. We have studied the influence of the relative intensities of pump and probe field on the line profile. Due to the dispersion of the medium, the resonance frequency is nearly independent of the geometrical length of the resonator.
54 citations
TL;DR: In this paper, an experimental realization of power recycling in an interferometer with 30 m arm-length and suspended optical components has been achieved, and the power-recycling factor was about 300, corresponding to a light power of more than 100 W impinging on the beam splitter.
34 citations
TL;DR: In this article, the frequency response of Michelson-and Sagnac-based interferometers were evaluated and compared, considering the application for gravitational-wave detection, and it was shown that SagnAC-based Interferometers have some interesting features, but in general do not offer advantages over Michelsonbased ones for the detection of gravitational waves.
25 citations
TL;DR: In this article, the amplitude and phase of a single-year orbital motion around the Sun were modulated to extract information from the signal, and the results of the semi-analytic calculations were interpreted to determine the angular resolution of the source.
Abstract: LISA is a space-borne, laser-interferometric gravitational wave detector currently under study by the European Space Agency. We give a brief introduction about the main features of the detector, concentrating on its one-year orbital motion around the Sun. We show that the amplitude as well as the phase of a gravitational wave is modulated due to that motion, allowing us to extract information from the signal. The most common way to estimate the parameters which characterize a signal present in a noisy data stream is to use the matched filtering technique. A brief review of the theory of parameter estimation, based on the work of Finn and Cutler, will be given. We carried out a simulation of the detection of a monochromatic gravitational wave based on that theory and focusing on estimating the angular parameters of the source. The results of the semi-analytic calculations are presented in detail and interpreted to determine the angular resolution of LISA.
24 citations
TL;DR: In this paper, the authors investigated the influence of preparing monolithic test masses on internal Q's of suspended substrates and found that the effect of preparing these suspensions on the internal Q's was negligible.
23 citations
TL;DR: In this paper, a nonlinear analysis is performed using the technique of continued fractions with respect to the dressedstate basis of a strong pumping laser for obtaining strong negative dispersion without absorption in the central resonance structure of the spectrum of a bichromatically driven two-level system.
Abstract: The possibility of obtaining strong negative dispersion without absorption in the central resonance structure of the spectrum of a bichromatically driven two-level system is investigated. A nonlinear analysis is performed using the technique of continued fractions with respect to the dressedstate basis of a strong pumping laser. We discuss the transition between the two regimes of the monochromatic driving case with a weak probing laser and of nearly equally strong lasers in terms of the contributions from coherences and populations of these dressed states. In contrast with the strong dependence of the Rabi side bands on probe field intensity, we find a remarkable stability of the negative dispersion in the central resonance structure.
12 citations
01 Jan 1997
7 citations
TL;DR: In this paper, the authors discuss LISA's ability to resolve different polarizational states of a gravitational wave with fixed frequency and amplitude, and calculate the 1- uncertainty range for measuring the orientation of the source.
Abstract: We discuss LISA's ability to resolve different polarizational states of a gravitational wave with fixed frequency and amplitude. Assuming a binary as the source of the gravitational wave, its orientation is connected with the polarization of the gravitational wave emitted. Using methods of signal processing, we calculate the 1- uncertainty range for measuring the orientation of the source.
5 citations