Engineering topics
Publications and source records attributed to Gursel, Y..
In a 3-baseline interferometer fourteen metrology gauges are used to monitor changes in the two baselines and calculate the length of the third. Simulation for estimating the third baseline indicates measurement capability of better than 1 nm error.
In this paper, the gauge construction details, the results of the gauge accuracy tests as well as the final path-length modulator performance details are presented.
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In this paper, the details of the design, construction and performance of the attitude control system are presented. The attitude control system has been used to meet certain SIM requirements. An example of this performance test is also included.
In this paper the details of the design, construction and performance of these triplet of interferometers are presented.
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The Palomar Testbed Interferometer (PTI) is a long-baseline infrared interferometer located at Palomar Observatory, California. It was built as a testbed for interferometric techniques applicable to the Keck Interferometer. First fringes were obtained in 1995 July. PTI implements a dual-star architecture, tracking two stars simultaneously for phase referencing and narrow-angle astrometry. The three fixed 40 cm apertures can be combined pairwise to provide baselines to 110 m. The interferometer actively tracks the white-light fringe using an array detector at 2.2 microns and active delay lines with a range of +/-38 m. Laser metrology of the delay lines allows for servo control, and laser metrology of the complete optical path enables narrow-angle astrometric measurements. The instrument is highly automated, using a multiprocessing computer system for instrument control and sequencing.
The Palomar Testbed Interferometer (PTI) is a long-baseline infrared interferometer located at Palomar Observatory, California.
The proposed Space Interferometry Mission (SIM) spacecraft designs include high resolution stellar interferometers for micro-arc-second accuracy astrometric measurements.
The Palomar Testbed Interferometer (PTI) is an infrared, phase-tracking interferometer in operation at Palomar Mountain since July 1995. It was funded by NASA for the purpose of developing techniques and methodologies for doing narrow-angle astrometry for the purpose of detecting extrasolar planets.
The micro-arcsecond metrology testbed (MAM) is a high-precision long baseline interferometer inside a vibration-isolated vacuum tank.
The Space Interferometry Mission (SIM) relies on the combination of interferometry with a metrology system capable of measureing picometer relative length changes and micrometer absolute lengths.
The proposed Space Interferometry Mission (SIM) spacecraft carries high resolution stellar interferometers for micro-arc-second accuracy astrometric measurements.
Heterodyne interferometers have been commercially available for many years. In addition, many versions have been built at JPL for various projects. This activity is aimed at improving the accuracy of such interferometers from the 1-30 nanometer level to the picometer level for use in the proposes Stellar Interferometry Mission (SIM) as metrology gauges.
We discuss the effect of mirror birefringence in two optical schemes designed to detect the quantum-electrodynamics (QED) predictions of vacuum birefringence under the influence of a strong magnetic field, B. Both schemes make use of a high finesse Fabry-Perot cavity (F-P) to increase the average path length of the light in the magnetic field. The first scheme, which we called the frequency scheme, is based on measurement of the beat frequency of two orthogonal polarized laser beams in the cavity. We show that mirror birefringence contributes to the detection uncertainties in first order, resulting in a high susceptibility to small thermal disturbances. We estimate that an unreasonably high thermal stability of ~10-9 K is required to resolve the effect to 0.1%. In the second scheme, which we called the polarization rotation scheme, laser polarized at 45 relative to the B field is injected into the cavity.