US 12,104,902 B2
Method and apparatus for detecting changes in direction of a light beam
Johann Engelhardt, Bad Schoenborn (DE)
Assigned to Max-Planck-Gesellschaft zur Foerderung der Wissenschaften e. V., Munich (DE)
Filed by Max-Planck-Gesellschaft zur Foerderung der Wissenschaften e.V., Munich (DE)
Filed on Apr. 20, 2021, as Appl. No. 17/234,982.
Application 17/234,982 is a continuation of application No. PCT/EP2019/078245, filed on Oct. 17, 2019.
Claims priority of application No. 10 2018 126 544.1 (DE), filed on Oct. 24, 2018.
Prior Publication US 2021/0239452 A1, Aug. 5, 2021
Int. Cl. G01B 9/02 (2022.01); G01B 9/02098 (2022.01); G01B 11/26 (2006.01); G02B 5/04 (2006.01); G02B 21/00 (2006.01); G06T 7/33 (2017.01); G06T 7/73 (2017.01)
CPC G01B 9/02098 (2013.01) [G01B 9/02041 (2013.01); G01B 11/26 (2013.01); G02B 5/04 (2013.01); G02B 21/0036 (2013.01); G02B 21/008 (2013.01); G06T 7/33 (2017.01); G06T 7/74 (2017.01)] 20 Claims
OG exemplary drawing
 
1. A method of detecting changes in direction of a collimated coherent light beam, the method comprising
splitting the light beam into at least two partial light beams,
superimposing the at least two partial light beams to form a spatial interference pattern displaying a plurality of light intensity minima and light intensity maxima alternatingly following to one another in at least one transverse direction oriented transversely to an average propagation direction of the at least two partial beams,
focusing the superimposed at least two light beams into at least one focus positioned in front of a camera,
registering pictures of at least a part of the spatial interference pattern including a plurality of the light intensity maxima with the camera,
analyzing the spatial interference pattern to determine an average shift of the plurality of light intensity maxima in the at least one transverse direction from the pictures registered with the camera, and
deducing a change in angular orientation of the collimated coherent light beam in the at least one transverse direction from the average shift of the plurality of light intensity maxima in the at least one transverse direction.