| 摘要 |
PURPOSE:To optimize a resonator constantly and obtain stable oscillation of a high quality horizontal mode laser beam from the start of oscillation by a method wherein a detector which observes intensity distribution is provided on a passage of a simulation beam and a resonator mirror angle adjusting mechanism is linked with a resonator mirror. CONSTITUTION:As an He-Ne laser beam, which is introduced into an unstable type resonator through a small hole at the center of a concave resonator mirror 2, is reflected between a convex resonator mirror 3 and the concave resonator mirror 2 back and forth for about 50 turns and then taken out by a taking-out mirror 4, the condition of the unstable type resonator can be evaluated by observing the intensity distribution of a simulation beam 17. When the resonator is adjusted properly, the beam 17 has a perfect annular shape but, if the setting angles of the resonator mirrors 2 and 3 do not match each other, the beam 17 is not axially symmetrical. While laser is being oscillated, the laser beam 6 and the simulation beam 17 are taken out by the taken-out mirror 4 and separated by a filter 13 and the beam 17 enters a four quadrants detector 14. Then the angle of the concave resonator mirror 2 is so adjusted as to make the deviation zero by rotating angle adjusting pulse motors for X-axis and Y-axis of a resonator mirror angle adjusting mechanism 15 independently. |
