An Opto-Isolator And A Laser Processing Apparatus Using The Same

Abstract

An opto-isolator including a Faraday rotator comprised of a crystal cylinder formed into a cylinder using a crystal that rotates polarized light; an enclosing tube surrounding the crystal cylinder; two cooling tubes each sized and positioned to allow both ends of the outer peripheral surface of the crystal cylinder to be inscribed within the cooling tubes and both end sections of an inner peripheral surface of the enclosing tube to be circumscribed around the cooling tubes; passages formed within the cooling tubes; a cooling medium circulating through a space formed among the crystal cylinder, the enclosing tube, and the two cooling tubes, and the passages; and a magnet disposed in an outer periphery of the enclosing tube. The opto-isolator further includes two polarizers respectively disposed on the optical path of light entering the Faraday rotator and an optical path of the light exiting the Faraday rotator.

1 - 6 . (canceled) 
     
     
         7 . An opto-isolator comprising:
 a Faraday rotator comprised of:
 a crystal cylinder formed into a cylinder using a crystal that rotates polarized light, 
 an enclosing tube surrounding a side face of the crystal cylinder, 
 two cooling tubes each sized and positioned to allow both ends of an outer peripheral surface of the crystal cylinder to be inscribed within the cooling tubes and both end sections of an inner peripheral surface of the enclosing tube to be circumscribed around the cooling tubes, 
 passages formed within the cooling tubes, 
 a cooling medium circulating through a space formed among the crystal cylinder, the enclosing tube, and the two cooling tubes, and the passages, and 
 a magnet disposed in an outer periphery of the enclosing tube; and 
   two polarizers respectively disposed on an optical path of light entering the Faraday rotator and an optical path of light exiting the Faraday rotator.   
     
     
         8 . A laser processing apparatus comprising:
 an opto-isolator according to  claim 7 .   
     
     
         9 . The opto-isolator according to  claim 7 , wherein:
 the crystal cylinder rotates polarized light by 45 degrees, and   a λ/2 wave plate is disposed in a position in contact with the cooling tube, on an optical path of light emitted from the crystal cylinder   
     
     
         10 . A laser processing apparatus comprising:
 an opto-isolator according to  claim 9 .