MEMS as Ultrafast X-ray Optics for Manipulating X-ray Pulses with Picosecond Resolution

Our research unveiled a novel application of torsional MEMS, showcasing their ability to manipulate hard X-ray pulses effectively. This manipulation occurs on a time scale from 300 ps down to an astonishing 50 ps, a range comparable to or even shorter than the pulse length of X-rays from synchrotron sources. This ultra-fast X-ray modulation is achieved by timing nonlinear micro-mechanical resonators with a synchrotron storage ring to diffract X-ray pulses through the narrow Bragg peak of the single-crystalline material. We have achieved an unprecedentedly fast maximum angular velocity exceeding 10⁷ degrees/s while maintaining the maximum linear velocity well below sonic speed and material break-down limit. Furthermore, we have demonstrated the potential of highly ultrafast X-ray optics-on-a-chip based on MEMS. These optics can modulate hard X-ray pulses exceeding 350 MHz, a frequency 10³ times higher than any other mechanical modulator, with a pulse purity >10⁶ without compromising the spectral brilliance.