There is a separate unwinding station for the mother roll that is equipped with an electromagnetic brake to adjust unwind-ing tension. The Orion II provides the entire range of Calemard cutting techniques, thermal slitting, crush slitting, ultrasonic cutting, and floating razor blade slitting, or any combination of them. However, this precision can be compromised by temperature variations that can misalign the laser's resonator, which supports the optical mirrors used to focus the beam. Laser manufacturers must build resonator support structures to stabilize their instruments' optical structure as much as possible. The highly polished bars of Super Invar 32-5 alloy maintain the mirror alignment required by this Coherent Laser.
Horizontal rods support the mirrors.
Coherent Laser Group of Santa Clara, Calif., incorporated rods made of Super Invar 32-5 alloy, developed by Carpenter Technology Corp. of Reading, Pa., in its laser resonator support structures. The iron, nickel, and cobalt alloy was chosen because of its extremely low coefficient of thermal expansion and its high thermal mass. For example, support rods of aluminum and graphite possessed the requisite low coefficient of thermal expansion, but not the high thermal mass that buffers temperature change. According to Paul Ginouves, senior product manager at Coherent Lasers, the Super Invar alloy rods provide the highest immunity to thermal transients over a wide range of temperature conditions. The plan calls for a 2,500-lb. precision draw bench made by the joint efforts of engineering companies from three countries.