Patent ID: 7957449
Filing Date: 2011-06-07
Classification: G03F,H01S

Abstract:
1. A two-stage laser system for aligners, comprising an oscillation-stage laser and an amplification-stage laser that inputs laser light oscillated by said oscillation-stage laser, amplifies and outputs the laser light, and said oscillation-stage laser and said amplification-stage laser each comprising a discharge electrode in a chamber filled with a laser gas, wherein the output light of said oscillation-stage laser has a divergence angle, said amplification-stage laser comprises a ring resonator including a partial reflecting mirror that serves both as an input of the oscillation-stage laser light and an output of laser light amplified, a first total-reflection mirror that reflects the laser light input via said partial reflecting mirror and transmits said laser light through a discharge area of the discharge electrode of said amplification-stage laser, and a plurality of total-reflection mirrors that transmits again the light transmitted through said discharge area by the first total-reflection mirror of said amplification-stage laser to the discharge area of the discharge electrode and return the light back to the position of said partial reflecting mirror, a plane formed by a loop laser optical axis defined by the plurality of total-reflection mirrors and the partial reflecting mirror is substantially orthogonal to a discharge direction of the discharge electrode, thus the output light of said oscillation-stage laser passes through the discharge area of the discharge electrode of said amplification-stage laser two times in one way per loop, and said partial reflecting mirror and said plurality of total-reflection mirrors are each formed of a plane.