公开(公告)号：EP1041689A4

公开(公告)日：2006-03-01

申请号：EP99970514

申请日：1999-10-08

申请人： USHIO ELECTRIC INC

发明人： TADA AKIFUMI ,  SEKI KYOHEI

IPC分类号： H01S3/225 ,  H01S3/08 ,  H01S3/1055 ,  H01S3/139

CPC分类号： H01S3/08009 ,  H01S3/225

摘要： An excimer laser comprises a band-narrowing optical system (6) having an advantage that the oscillation center wavelength hardly varies with temperature and provided with a Littrow-mounted reflection-type diffraction grating (3) and a beam-expanding optical system (5) disposed on the light-incidence side of the reflection-type diffraction grating (5). The beam expanding optical system (5) is composed of one or more beam expanding prism (11, 12) made of fluorite and one or more beam-expanding prism (13) made of synthetic quartz glass. The rate of change of the oscillation center wavelength with respect to temperature change is made small by considering the number, arrangement, and direction of prisms (11, 12, 13).