Showing papers on "Atom interferometer published in 1989"

Potential radiation-pressure-induced instabilities in cavity interferometers

Abstract: The mirrors of an interferometer may be rendered dynamically unstable by the radiation pressure of the sensing light. We assess the importance of this effect for optical cavities, concentrating in particular on proposed laser-interferometric gravitational wave detectors. Both broadband and narrow-band systems are considered. While the potential instabilities may well be important for cavities with weak suspensions, realistic gravitational wave detectors should not encounter any problems.

Interferometry with pulsed neutrons and test of a four-plate interferometer

Abstract: A fast neutron chopper produced neutron bursts shorter than the dimensions of the perfect crystal interferometer. Therefore, interference experiments became feasible where the beams inside the interferometer were completely separated. In another experiment, the properties of a four-plate interferometer was tested. Three coupled interferometer loops exist whose net phase shifts determine the intensity modulation behind the interferometer.

Small laser interferometer linked to laser source with an optical fiber.

Abstract: In a present laser interferometer system it is necessary to adjust the alignment between a laser source and a laser interferometer. The laser source is a heat source to be a disturbance in a precise length measurement, while the laser interferometer itself is large and its setting lacks flexibility. This study is performed in order to solve the practical disadvantage mentioned above, in which the small laser interferometer is linked to the laser source with an optical fiber so as to give full play to the flexibility in the case of the precise length measurement. The results of this study are shown as follows. (1) The influence of the disturbance mixing into the optical fiber can be cancelled by making differential interference signals by means of an electronic instrument. As a result, the resolution of the interferometer becomes high and the length measurement stable. (2) A small laser interferometer with an optical fiber has been developed with 10mm in measurable length and 0.05μm in resolution as a kind of contact type indicator. The length measurement error of the present interferometer is 0.13μm in 10mm. Another non-contact type laser interferometer has also been developed for vacuum.

A Stationary Hadamard Transform Interferometer

Abstract: Optical interferometers have been used extensively in many applied fields of science including chemistry and physics. Conventional interferometers have provided one, if not more of the following advantages over conventional dispersive spectrometers: (1) multiplex advantage (Fellgett's advantage) (2) high frequency precision (Connes' advantage) (3) high optical etendue' or throughput (Jacquinot advantage) There are many different types of optical interferometers available on the market today (e.g. Fizeau, Fabry-Perot, etc.,) but perhaps the most important, at least historically, is the Michelson interferometer. Most Fourier transform infrared spectrometers today are based on this design. The Michelson-type interferometer, which employs a beamsplitter and a moving mirror can be thought of as an amplitude splitting device. In other words, the original beam from the source is split in half by a beamspliiter with each half traversing one "arm" of the interferometer. One arm contains a movable mirror which modulates the interference fringe pattern generated as the two halves (i.e. each arm) are recombined by the beamsplitter. Since the movable mirror is translated with time, the interferogram is effectively recorded as a function of time. This temporal interferogram can be further related back to the optical path difference between the two arms of the interferometer. Stroke and Funkhouser proposed a Fourier transform spectrometer which created a spatial interferogram as opposed to the temporal interferogram produced by conventional Michelson-type interferometers. Some have referred to this device as a holographic spectrometer or source doubling interferometer. These devices can be thought of as wavefront splitting devices analogous to Young' double slit experiment or the Fresnel biprism. The primary source is split into two coherent secondary sources which will exhibit constructive and destructive interference in the plane. An appropiate Fourier transform of this interferogram will reconstruct the cosine frequency components of the primary source. There are many devices that make use of a spatial interferogram. Presently, in our laboratory, work is underway to develop a stationary Hadamard transform (HT) interferometer that utilizes a liquid crystal optical shutter array to encode a spatial interferogram created by a Fizeau interferometer design. Thus, the HT stationary interferometer becomes a no moving parts spectrometer.

Detecting Gravitational Waves by Laser Interferometers

Abstract: This paper describes detection of gravitational waves by laser interferometers. These are one of the two main types of proposed earth-based detectors of gravitational waves. The other type — bar detector, is described in papers by Pizzella and Pallotino in this volume.