| 摘要 |
PROBLEM TO BE SOLVED: To provide an ultranarrow-band mode laser device which effectively realizes ultranarrow-band mode of laser beam of fluorine laser which is subjected to laser oscillation and can stabilize central wavelength of the ultranarrow-band mode laser beam. SOLUTION: An etalon 5 has substrates 6a, 6b formed of an about 5 mm-thick wedge board consisting of fluorine-doped synthetic quartz. Since transmissivity in the wavelength of 157.6 nm in fluorine-doped synthetic quartz is as high as high as about 90% per cm, insertion loss by insertion of the etalon 5 is as small as about 10% and fluorine laser of high gain enables laser oscillation well. Therefore, it is possible to restrain variation of central wavelength of the spectrum of single line-mode laser beam and to realize ultranarrow-band mode thereof. |
