Abstract An interferometer for detecting the velocity of small particles in a fluid includes relatively static means comprising a source of coherent radiation and a beam splitter means mounted in a fixed relationship for directing beams of coherent radiation from the source along two predetermined paths comprising a test path which will pass through the fluid under test and a reference path, and a scattering means mounted in the reference path for scattering the radiation in that path into a plurality of angles; and rotatable means, comprising a structure pivotably connected to said static means and rotatable about an axis which passes through the intersection of the reference path with the scattering means and through the intersection of the test path with the fluid under test, and optical components mounted on the said structure comprising recombination means for interferingly recombining radiation scattered into identical angles from both paths and thereby forming interference fringes which indicate the local velocity of the fluid under test.
An interferometer for detecting the velocity of small particles in a fluid, which includes relatively static means comprising a source of coherent radiation and a beam splitter means mounted in a fixed relationship to one another for directing beams of coherent radiation from the said source along two predetermined paths one of which comprises a reference path and the other of which comprises a test path which will pass through the fluid under test, and a scattering means mounted in the reference path for scattering the radiation in that path into a plurality of angles; rotatable means comprising a structure pivotably connected to said relatively static means and rotatable about an axis which passes through the intersection of the reference path with the scattering means and through the intersection of the test path with the fluid under test, and optical components mounted on said structure and comprising recombination means for interferingly recombining radiation scattered through equal angles from both of said paths thereby to form interference fringes which indicate the local velocity of the fluid under test.
Claim 2
Dependent Claim
177 words
An interferometer for detecting the velocity of small particles in a fluid, which includes relatively static means comprising a source of coherent radiation and a beam splitter means mounted in a fixed relationship to one another for directing beams of coherent radiation from the said source along two predetermined paths one of which comprises a reference path and the other of which comprises a test path which will pass through the fluid under test, and a scattering means mounted in the reference path for scattering the radiation in that path into a plurality of angles; rotatable means comprising a structure pivotably connected to said relatively static means and rotatable about an axis which passes through the intersection of the reference path with the scattering means and through the intersection of the test path with the fluid under test, and optical components mounted on said structure and comprising recombination means for interferingly recombining radiation scattered through equal angles from both of said paths thereby to form interference fringes which indicate the local velocity of the fluid under test.
Claim 3
Dependent Claim
62 words
The interferometer of claim 1 further comprising detection means mounted in fixed relationship to said recombination means for detecting the recombined radiation, and frequency discrimination means connected to the said detection means for producing a signal the magnitude of which is proportional to the frequency difference between the radiation received from said test path and the radiation received from said reference path.
Claim 4
Dependent Claim
21 words
An interferometer as claimed in claim 1 wherein the test path and the reference path are of substantially equal optical length.
Claim 5
Dependent Claim
31 words
The interferometer of claim 1 wherein said interferometer is mounted on a rotatable turntable having an axis of rotation that is colinear with the said axis which passes through said intersections.