US 11,837,839 B2
Optical pulse stretcher, laser device, and electronic device manufacturing method
Hirotaka Miyamoto, Oyama (JP)
Assigned to Gigaphoton Inc., Tochigi (JP)
Filed by Gigaphoton Inc., Tochigi (JP)
Filed on Jan. 10, 2022, as Appl. No. 17/572,185.
Application 17/572,185 is a continuation of application No. PCT/JP2019/031233, filed on Aug. 7, 2019.
Prior Publication US 2022/0131328 A1, Apr. 28, 2022
Int. Cl. H01S 3/00 (2006.01); G02B 17/02 (2006.01); G02B 17/06 (2006.01); G03F 7/00 (2006.01); H01S 3/23 (2006.01)
CPC H01S 3/0057 (2013.01) [G02B 17/023 (2013.01); G02B 17/0657 (2013.01); G03F 7/70191 (2013.01); H01S 3/0014 (2013.01); H01S 3/2308 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A laser device, comprising:
a master oscillator configured to output pulse laser light;
a first optical pulse stretcher which includes a first delay optical system including a plurality of concave toroidal mirrors, and a beam splitter including a first surface and a second surface, causing a part of pulse laser light incident on the first surface to be transmitted in a first direction and output as a first beam and another part thereof to be reflected in a second direction and enter the first delay optical system, and causing a part of pulse laser light incident on the second surface from the first delay optical system to be reflected in the first direction and output as a second beam, and which is arranged on an optical path of pulse laser light output from the master oscillator; and
a second optical pulse stretcher arranged on an optical path of pulse laser light output from the master oscillator,
wherein the second optical pulse stretcher includes a second delay optical system including a plurality of concave toroidal mirrors, and a beam splitter including a third surface and a fourth surface, causing a part of pulse laser light incident on the third surface to be transmitted in a third direction and output as a first beam and another part thereof to be reflected in a fourth direction and enter the second delay optical system, and causing a part of pulse laser light incident on the fourth surface from the second delay optical system to be reflected in the third direction and output as a second beam, and
an optical path length of a delay optical path configured by the first delay optical system is different from an optical path length of a delay optical path configured by the second delay optical system.