公开(公告)号：US20170338616A1

公开(公告)日：2017-11-23

申请号：US15671580

申请日：2017-08-08

Applicant: Gigaphoton Inc.

Inventor： Akihiko KUROSU ,  Fumio KAWAMATA

IPC: H01S3/036 ,  F16C32/04 ,  H01S3/038

CPC classification number: H01S3/036 ,  F16C32/0446 ,  F16C32/0455 ,  F16C32/0485 ,  F16C32/0489 ,  F16C2360/46 ,  H01S3/038 ,  H01S3/08009 ,  H01S3/1305 ,  H01S3/1306 ,  H01S3/225

Abstract: A discharge excitation gas laser device may include a laser chamber in which a laser gas containing a halogen gas is encapsulated, a pair of discharge electrodes disposed to face each other inside the laser chamber, a fan disposed inside the laser chamber to make the laser gas flow between the pair of discharge electrodes, a motor for rotating the fan, a motor power supply for supplying power to the motor, a magnetic bearing configured to levitate the rotary shaft of the fan magnetically, a displacement sensor for detecting the position of the rotary shaft through a can, and a controller configured to measure the rotational speed of the fan on the basis of a detection signal from the displacement sensor and control the motor power supply in such a manner that the measured rotational speed becomes a target rotational speed.