Holographic Interferometry For Detection Of GW Radiation?
28 Jun 2005 4:03:40 UTC
Topic 189433
(moderation:
Would it be possible to detect GW radiation using a test mass in conjunction with a hologram of the test mass? For example, say the test mass is silicon crystal substrate, and has etched upon it an optimized test pattern. The hologram of the test pattern can be generated to depict the test mass in ideal conditions (null or initial field potential). In the detector, the hologram would be orthogonal to the test mass, and a beam splitter would be used to create the superposition of images, whose interference patterns are calibrated to detect h plus and h cross amplitudes.
Holographic Interferometry For Detection Of GW Radiation?
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What you are suggesting is a more complicated form of interferometry, as a holographic image is 'just' a very specific kind of interference pattern.
Your idea would be totally possible. The advantage would be that the way the experiment works would be easier for the lay parson to understand. The disadvantage is that it would add complexity to the design with no improvement in the data collection.
So the answer is: yes it is possible, but no, you would not do it that way in an experimental science lab.
Your design might be useful in a teaching lab, but probably not until we get to the stage that detecting gravity waves is no longer considered cutting edge but becomes a routine part of a degree curriculum.
~~gravywavy
RE: RE: Would it be
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The complexity of the interferometry would be the main advantage, since it translates directly to the sensitivity of the instrument. The hard part (as with LIGO) is calibration of the instrument. The ability to employ optimized test patterns can lead to amplification of desired effects, further improving sensitivity and signal filtering.
Another advantage is the size of the instrument. An entire 3-D array of test masses can be packaged on a single wafer. With a mode-locked laser to provide femtosecond imaging, over such a tiny region of spacetime, the idea is to create the necessary lattice of 'rods and clocks' required for proper measurements in the local inertial frame.
Perhaps the best part of the idea is the ability to hold the reference hologram in the 'virtual reality' of digital electronics, rather than on celluloid (where it would be subjected to perturbations from sources orthogonal to the test mass). The main advantage with this is obviously the elimination of most unwanted signals, and much noise.