| 摘要 |
PROBLEM TO BE SOLVED: To provide a laser device for radiation of a ultra-narrow bandwidth that oscillates with only one line without using an etalon, and in which the width of the wave in the line can be ultra-narrowed to about 0.2 pm. SOLUTION: A wedge plate 15 has a wedge, wherein an angleαformed with an incidence surface 15a and an exit surface 15b is about 4.4 deg.. Furthermore the wedge plate 15 is formed of a calcium fluoride board with the incidence surface 15a and the exit surface 15b that are both uncoated. A laser beam L1 is refracted at an angle of about 37.1 deg. with respect to perpendiculars of the incidence surface 15a at entering the wedge plate 15. Sine the wedge angleαis about 4.4 deg., the laser beam hits the exit surface 15b at an angle of about 32.7 deg. in the wedge plate 15. Thus an angleθ3 of the light exiting from the exit surface 15b is about 57 deg. that is a Brewster angle (arcsin (1.55865*sin 32.7)). |
