Final Diffraction Patterns of the Beam Splitters used in the Soft XRay Interferometer by a He-Ne Laser

Abstract

The soft x-ray(10㎚-100㎚) interferometer is a modified Mach-Zehnder type interferometer and it consists of two beam-splitters and four totally reflecting mirrors. The beam-splitters used here are 50% transmission and 50% reflection grating type. The diffraction patterns of beam splitters(1st B. S.) were investigated with a He-Ne laser. The diffraction patterns produced by the soft x-ray interferometer(2nd B. S.) were also investigated in intensities and positions. The diffraction patterns of 20 degree grazing incidence on the beam splitters(1st B. S.) show a circular array of spots. Both the reflected and the transmitted beams show the same patterns but symmetric circles on the screen. The maximum intensity appears roughly when n is in the zeroth and odd orders and the suppressed peak(missing order) appears when n is in the even orders. Intensities of 3 center fringes(n = 0, ±1) are stronger than others. These results confirm the reduced grating equation and make agree with the intensity distribution function. It was found that the final patterns produced by the soft x-ray interferometer(2nd B. S.) consisted of fine fringes which were caused by two of three diffraction beams that were arrived at the second beam-splitter.