| 摘要 |
PURPOSE:To manufacture the title laser oscillator emitting circular polarization output beams in a simple constitution by a method wherein a rear mirror is provided with the streak groups in concentric circular arrangement centered on an optical axis while the depth of the streaks is specified to be a medium between the skin effective depth of the rear mirror material in the laser oscillating wavelength and the laser oscillating wavelength itself. CONSTITUTION:The title oscillator composed of a single stage resonator simply comprising an output coupling mirror 4 and a rear mirror opposed to each other, however, the rear mirror 1 is not a conventional total reflection mirror but provided with concentric circular streaks. In other words, the rear mirror 1 is manufactured in high reflecting power on the arrangement of concentric circular E vector. At this time, laser beams 9 also display the similar polarization characteristics. When such laser beams are focussed to be applied to a cutting process, the polarizing direction is never a circular polarization but becomes circular symmetry displaying characteristics similar to those when the circular polarization is used. Through these procedures, the title laser oscillator can be provided with the same characteristics as those of circular symmetrical polarization beams to be applied to the cutting process etc. as the circular polarization beams. |
