公开(公告)号：WO2020249339A1

公开(公告)日：2020-12-17

申请号：PCT/EP2020/063100

申请日：2020-05-11

Applicant: ASML NETHERLANDS B.V.

Inventor： JANSEN, Maarten, Jozef ,  MRIDHA, Manoj Kumar ,  VAN DER PASCH, Engelbertus, Antonius, Fransiscus

IPC: G01B9/02 ,  G01J9/02 ,  G03F7/20 ,  G03F9/00

Abstract: The invention provides an interferometer system to determine a position of a movable object, comprising: a laser source to provide a radiation beam, an optical system arranged to split the radiation beam into a first beam along a first optical path and a second beam along a second optical path, and recombine the first beam and the second beam to a recombined beam, a detector to receive the recombined beam and to provide a detector signal based on the received recombined beam, and a processing unit, wherein a first optical path length of the first optical path and a second optical path length of the second optical path have an optical path length difference, wherein the processing unit is arranged to determine a mode hop of the laser source on the basis of a phase shift in the detector signal.

公开(公告)号：WO2021170333A1

公开(公告)日：2021-09-02

申请号：PCT/EP2021/051901

申请日：2021-01-28

Applicant: ASML NETHERLANDS B.V.

Inventor： LIEDECKE, Christian ,  BAGGEN, Marcel, Koenraad, Marie ,  JANSEN, Maarten, Jozef ,  MRIDHA, Manoj Kumar

IPC: G01B9/02 ,  G01B11/00 ,  G03F7/20

Abstract: The invention relates to an interferometer system comprising a light source to provide a radiation beam, an optical fiber, and an optical unit arranged on an object of interest comprising a fiber end holding device to hold a measurement end of the optical fiber, and a reflector arranged on the object of interest. The measurement end of the optical fiber being arranged to partially transmit and partially reflect the radiation beam to split the radiation beam in a measurement beam and a reference beam, the optical unit is arranged to direct the measurement beam to a reflective surface on the reference object, the reflector is arranged to reflect the measurement beam after reflection on the reflective surface back to the reflective surface, the optical unit is arranged to receive the reflected measurement beam and guide the reflected measurement beam to the end surface.