Method and apparatus for interferometric measurement
(English)Patent (Other (popular science, discussion, etc.))
A method for interferometric measurement comprises emitting waves onto a reference surface (1) and onto a measured object (2), which each reflects a part of the emitted waves, and receiving both the reflected parts of the waves by the same receiver (4). In the receiver the parts of the waves generate a representation of the measured object (2) in the form of an interferogram, from which the form of the measured object (2) is determined. The emitted waves comprise waves of three well-defined wavelengths nu1, nu2 and nu3, where nu1<> nu2<> nu3, which wavelengths are chosen to substantially satisfy the mutual relation nu1=(nu2.nu3)/(2.nu3-nu2) and generate an interferogram each in the receiver (4). An apparatus suited to implement the method comprises a light source (3) for emitting light, a reference surface for reflecting a first part of said light, and a receiver (4) which is arranged to receive the first part of the light and a second part of the light, reflected by a measured object (2). The light source is arranged to simultaneously emit light of the three above-mentioned well-defined wavelengths.
Research subject Industrial Electronics
IdentifiersURN: urn:nbn:se:ltu:diva-36871Local ID: 8842b260-5144-11db-9592-000ea68e967bOAI: oai:DiVA.org:ltu-36871DiVA: diva2:1010318
US US6493092, WO0020824 (A1), EP1117973 (A1), EP1117973 (A0), SE9803326 (L), SE521927 (C2) (2002-12-10)
Godkänd; 2002; 20060926 (ysko)2016-10-032016-10-03Bibliographically approved