US 12,359,910 B2
Device and method for measuring interfaces of an optical element
Sylvain Petitgrand, Caissargues (FR); and Alain Courteville, Congenies (FR)
Assigned to FOGALE NANOTECH, Nîmes (FR)
Appl. No. 18/245,605
Filed by FOGALE NANOTECH, Nîmes (FR)
PCT Filed Sep. 9, 2021, PCT No. PCT/EP2021/074816
§ 371(c)(1), (2) Date Mar. 16, 2023,
PCT Pub. No. WO2022/058236, PCT Pub. Date Mar. 24, 2022.
Claims priority of application No. 2009566 (FR), filed on Sep. 21, 2020.
Prior Publication US 2023/0332885 A1, Oct. 19, 2023
Int. Cl. G01B 11/24 (2006.01)
CPC G01B 11/2441 (2013.01) 20 Claims
OG exemplary drawing
 
1. A measurement device, for measuring the shape of interfaces to be measured of an optical element comprising a plurality of interfaces, the device comprising:
at least one low-coherence light source;
at least one optical sensor; and
an interferometric device illuminated by said light source or sources and configured for:
shaping at least one measurement beam and at least two reference beams;
directing said at least one measurement beam to the optical element so as to pass through the interfaces to be measured;
directing the light coming from at least two interfaces to be measured to the optical sensor or sensors;
said at least one measurement beam and at least two reference beams being incidents on the at least one optical sensor with incidence angles different from each other,
said optical sensor or sensors being globally configured to detect selectively at least two interference signals resulting respectively from interferences between the at least one measurement beam reflected by one of said at least two interfaces to be measured and one of the at least two reference beams;
the measurement device also comprising:
positioning means configured to position a coherence area at the level of each of the at least two interfaces to be measured; and
digital processing means configured to produce, from the interference signals, an item of information of the shape of each of said interfaces to be measured according to a field of view.