公开(公告)号：US11569628B2

公开(公告)日：2023-01-31

申请号：US17268778

申请日：2019-08-05

Applicant: ASML Netherlands B. V.

Inventor： Herman Philip Godfried ,  Wilhelmus Patrick Elisabeth Maria Op 'T Root

IPC: G03F7/20 ,  H01S3/00 ,  G02B27/14 ,  G02F1/01

Abstract: An apparatus (10) for increasing a pulse length of a pulsed radiation beam, the apparatus comprising: a beam splitter (16) configured to split an input radiation beam (18) into a first beam (24) and a second beam (22); an optical arrangement (12, 14), wherein the beam splitter and the optical arrangement are configured such that at least a portion of the first beam is recombined with the second beam into a modified beam after an optical delay of the first beam caused by the optical arrangement; and at least one optical element (30) in an optical path of the first beam, the at least one optical element configured such that the phase of different parts of a wavefront of the first beam is varied to reduce coherence between the first beam and the second beam.