In X-ray Talbot-Lau grating interferometer, the system layout is determined by Talbot effect and Lau effect. Generally, the imaging systems should be arranged according to the designed parameters. In this paper, we report a flexible X-ray Talbot-Lau grating interferometer, which is similar to non-interferometric phase contrast imaging system. The visibility remains almost unchanged when only Lau condition is satisfied. This is exciting, especially for shorter system than the designed one. We analyze the reasons of the relaxed Talbot condition, which is validated by simulation. Finally, we report experiment-tal results of some samples, imaged by the flexible interfero-meter under conditions of three system lengths.

X-ray phase-contrast imaging,Flexible Talbot-Lau grating interferometer,Talbot effect