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I have my suspicions too, although there is a sort of reciprocity argument that justifies the statement. The slips (slits?) are, presumably there to suppress off axis beams entering the two gas tubes and causing crosstalk between the two paths. If they are downstream of the tubes, would they achieve the same effect? I am not familiar with the Rayleigh Interferometer and I may have misunderstood what they do. The problem I am referring to would be eliminated if the two tubes were run through holes in an opaque block.HotFurnace said:My teacher say nothing will change in the interference pattern but I doubt his answer.
HotFurnace said:View attachment 236575
What will change if we place the slips in front of the converging lens instead of behind the collimating lens? My teacher say nothing will change in the interference pattern but I doubt his answer.
That seems to imply that the interferogram would be a sinx/x type pattern - due to the lens aperture- or perhaps the aperture of the gas tubes. A google search doesn't seem to reveal the shape of the actual pattern but it does seem to suggest from the plan and elevation diagrams in some links that each gas tube is above one axis and that there is an air path reference 'under' each tube so that two gases can be compared with air.Andy Resnick said:Note- as drawn, the interfereogram will be the same size as the pinhole unless the lenses have differing focal lengths.
sophiecentaur said:That seems to imply that the interferogram would be a sinx/x type pattern - due to the lens aperture- or perhaps the aperture of the gas tubes. A google search doesn't seem to reveal the shape of the actual pattern but it does seem to suggest from the plan and elevation diagrams in some links that each gas tube is above one axis and that there is an air path reference 'under' each tube so that two gases can be compared with air.
I need a noddy reference - but not too noddy as to omit the most important bits!
That makes sense to me but some of the diagrams on Google Images seem to divide the field into quadrants with two dummy air channels. I guess you are suggesting that the diagonally opposite air path would be used as reference for each gas tube. I must say, I was very disappointed not to find some actual images of the interferograms with a search. After all, that's what it's all about.Andy Resnick said:That relative phase Δ will only depend on the two gases *if* the gas cells are symmetric about the optical axis.
A Rayleigh interferometer is a scientific instrument used to measure the wavelength and frequency of light. It works by splitting a beam of light into two beams that travel different paths and then recombining them to create an interference pattern.
A Rayleigh interferometer uses a beam splitter, mirrors, and a detector to create an interference pattern. The beam splitter divides the incoming light beam into two beams that travel different paths. The two beams are then recombined and interference occurs, which can be measured by the detector.
The main purpose of a Rayleigh interferometer is to measure the wavelength and frequency of light. It is also used in various scientific experiments and research studies, such as in spectroscopy and in the study of atomic and molecular structures.
One of the main advantages of a Rayleigh interferometer is its high precision in measuring the wavelength and frequency of light. It is also a non-destructive method, meaning it does not alter or damage the light beam during measurement. Additionally, it can be used to measure very small changes in the wavelength, making it a highly sensitive tool.
One limitation of a Rayleigh interferometer is that it can only measure the wavelength and frequency of light in a single direction. It is also sensitive to external vibrations, which can affect the accuracy of the measurements. Additionally, it is a complex instrument and requires a skilled operator to set up and interpret the results.