| 摘要 |
PROBLEM TO BE SOLVED: To make performing a stable operation for a long time, by preventing a sealing ring for cooling water which contacts to both terminal surfaces of a filter cylinder by a spring from degrading caused by exciting light radiation without accompanying with leaking of the cooling water. SOLUTION: This device is comprised of inserting holes 3a and 3b of a laser rod 1 and an exciting lamp 2 being provided, an O ring 6 which is equipped in a recess gap 5a formed on an end cap 5 and contact with a terminal face of a filter cylinder 3 by a spring, sealing a space between the terminal face of the filter cylinder 3 and the end cap 5 to support the filter cylinder 3, a light screen ring 7 being provided between an inside peripheral face of the recess gap 5 and the O ring 6. The light screening ring 7 shuts a gap t which is formed between the end gap 5 to allow an extension of the filter cylinder 3 caused by a thermal expansion, reflects an excitation light which is radiated from the exciting lamp 2 and directly irradiates the O ring 6 via the gap t and prevents the O ring 6 from degrading caused by the irradiation. |
