With the development of the next generation of synchrotron radiation and free electron lasers, x-ray measurement and imaging, such as x-ray holography and biochemical microscopy, has become a hot spot again. In many x-ray imaging methods, holography, first proposed by Gabor in 1948, is an attractive approach to reconstruct the complex object. However, phase-shifting digital holography is difficult to be operated due to the lack of the suitable x-ray phase shifter.

Recently, researchers from Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences, have introduced the concept of Fibonacci-Billet split lens into inerferometry and successfully realized three phase-locked copies of the test object, which met the requirement of phase-shifting interferometry. This research was published in Optics Express.

In the following experiment, they designed the amplitude-only Fibonacci-Billet split sieve and used them to image an amplitude-only object that was fabricated on a chrome plate.

For the traditional phase-shifting interferometry, the reference beam is phase shifted in general. Here they not only realized the phase shift of the reference beam but also simultaneously obtained three phase-locked copies of test object in the object beam path.

Furthermore, they successfully reconstructed the intensity and phase distributions of the test object. The experimental results agreed well with the theoretical analysis and verified the validity of the phase shift function of Fibonacci-Billet split sieve.

In developing the next generation of synchrotron light source (free-electron lasers), the amplitude-only Fibonacci-Billet split sieve will offer an opportunity for x-ray holography, biochemical microscopy at short wavelengths, and x-ray spectroscopy in physical and life sciences.

This work was supported by the National Natural Science Foundation of China and Youth Innovation Promotion Association of the Chinese Academy of Sciences.

Fig.1. Fibonacci-Billet split sieve and its imaging path. (Image by SIOM)

Fig.2. Reconstructed intensity (a) and phase distributions (b). (Image by SIOM)