Abstract
Hard X-ray Fabry–Perot resonators using Bragg-back-reflection has been proposed and explored since 1967. The ideas were brought into effect until 2005 when Chang et al. directly observed cavity resonance fringes in a Si crystal with the size of 40~150 μm. The performance of cavities using Si (12 4 0) back diffraction at 14.4388 keV with energy resolution ΔE of 0.36 meV was barely satisfactory for the intrinsic limits of crystal –based resonators from crystal absorption and 24-beam diffractions.In this thesis, we proposed two models of resonators to improve the practicability of hard X-ray resonators:(1) Using Al2O3 ( 0 0 0 30) back diffraction for X-ray resonators at 14.3148 keV: For its less absorption and hexagonal structure, the resonator of sapphire crys-tals underwent a pure 2-beam diffraction which could enhance the resonance interference and improve finesse compared with the one of silicon crystals.(2) Hard X-ray resonators with inclined-incidence geometry:Utilizing one of the multiple diffractions as incident beam to generate back dif-fraction in a crystal cavity for resonance and demonstrate FP resonance with ul-trahigh efficiency, highly purified resolving power in the sub-meV range and low background.Both the experimental results show clear resonance fringes for the enhance-ment in Finesse and peak efficiency, especially for the inclined incidence, only by changing the path of incidence, the visibility was enhanced nearly 30 times than normal incidence. The compact-sized resonator with these promising fea-tures can be widely implemented to different energies and materials and antici-pated to apply to ultrahigh-resolution X-ray optics for X-ray diffraction, spec-troscopy, and imaging applications.