Micro machining device

TL;DR: In this article, a micro machining work is irradiated with a femtosecond laser beam and the work is fixed at a focus position with a minimum laser beam intensity given on the basis of the detected output of the third optical detector 67C.

Abstract: PROBLEM TO BE SOLVED: To accurately process a micro machining in the order of nanometer. SOLUTION: The intensity of a reflected light from a work 110 which is irradiated with a femtosecond laser beam is detected with first and second optical detectors 67A and 67B, the intensity of a plasma light generated by abrasion is detected with a third optical detector 67C, a moving table 11 is controlled with a first controlling computer 61 so that the work 110 is fixed at a focus position on the basis of the detection outputs of the first and the second optical detectors 67A and 67B, a micro moving table 13, which finely moves the work 110 mounted on the moving table 11 in the direction of the optical axis of a condensing part 50 of the femtosecond laser beam, is so controlled with a second controlling computer 62 that the work 110 is fixed at a more accurate focus position with a minimum laser beam intensity given on the basis of the detected output of the third optical detector 67C, and the computer 62 controls a power controlling part 30 which controls the power of the femtosecond laser beam.