US 11,906,753 B2
Optical system in particular for microlithography
Johannes Kraus, Theilheim (DE)
Assigned to Carl Zeiss SMT GmbH, Oberkochen (DE)
Filed by Carl Zeiss SMT GmbH, Oberkochen (DE)
Filed on Apr. 13, 2021, as Appl. No. 17/229,167.
Application 17/229,167 is a continuation of application No. PCT/EP2019/071886, filed on Aug. 14, 2019.
Claims priority of application No. 102018218064.4 (DE), filed on Oct. 22, 2018.
Prior Publication US 2021/0231965 A1, Jul. 29, 2021
Int. Cl. G02B 27/14 (2006.01); G02B 1/02 (2006.01); G03F 7/00 (2006.01)
CPC G02B 27/14 (2013.01) [G02B 1/02 (2013.01); G03F 7/70025 (2013.01); G03F 7/70566 (2013.01); G03F 7/70958 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An optical system, comprising:
a beam splitter comprising a light entry surface having a surface normal, wherein:
the beam splitter is arranged in the optical system so that, during use of the optical system, angles of incidence with respect to the surface normal lie in a range of 45°±5°; and
the beam splitter is produced in the [110] crystal cut.