Ultrafast photonic micro-systems to manipulate hard X-rays at 300 picoseconds

Abstract

Time-resolved and ultrafast hard X-ray imaging, scattering and spectroscopy are powerful tools for elucidating the temporal and spatial evolution of complexity in materials. However, their temporal resolution has been limited by the storage-ring timing patterns and X-ray pulse width at synchrotron sources. Here we demonstrate that dynamic X-ray optics based on micro-electro-mechanical-system resonators can manipulate hard X-ray pulses on time scales down to 300 ps, comparable to the X-ray pulse width from typical synchrotron sources. This is achieved by timing the resonators with the storage ring to diffract X-ray pulses through the narrow Bragg peak of the single-crystalline material. Angular velocities exceeding 107 degrees s−1 are reached while maintaining the maximum linear velocity well below the sonic speed and material breakdown limit. As the time scale of the devices shortens, the devices promise to spatially disperse the temporal width of X-rays, thus generating a temporal resolution below the pulse-width limit.

An Efficient and Stable Perovskite Solar Cell with Suppressed Defects by Employing Dithizone as a Lead Indicator

“…After reacting with the organic amine to form perovskite, the XRD peaks (Supporting Information, Figure S3) at 2 theta = 14.18, 23.98, and 28.38 can be ascribed to the (110), (211), and (220) crystal planes of (Cs 0.05 FA 0.54 MA 0.41 )Pb(I 0.98 Br 0.02 ) 3 perovskite, respectively. [24] Neither new peaks, nor any peak shifts were observed, indicating that the addition of DTZ will not influence the main composition of perovskite. The highest intensity of (220) plane for Perovskite-c manifests that the moderate DTZ (0.06 mg mL À1 ) could be used to enhance the crystallization of perovskite, which profits from that the coordination roles between DTZ and PbI 2 can retard the reaction rate between PbI 2 and organic amine solution, enhancing the crystallization intensity of perovskite further.…”

On-Chip Frequency Tuning of Fast Resonant MEMS Scanner

“…Manufacturing tolerances of specifically high frequency resonance MEMS mean that even 0.1% deviations in the resonance frequency can lead to significant shifts in the desired update rate, and would require adjustment mechanisms for frequency tuning. Approaches for frequency tuning of resonant MEMS micromirrors have so far mostly focused on the removal or addition of material, for example by focused ion beam milling and removal of material from the edges of a scanner mirror plate [16], which has achieved a scan frequency adjustment of 3.5%. While this passive tuning method does not increase the power consumption of the scanner it also does not allow active adjustment during operation, is not reversible and not mass-fabrication compatible.…”

Design of a ZnO/Poly(vinylidene fluoride) inverse opal film for photon localization-assisted full solar spectrum photocatalysis

“…Owing to its PBG and slow light effects, PC structure has attracted great interest due to its potential application for improving light harvesting in photocatalysis [33][34][35][36]. The PBG effect can be described as light within the wavelength region of the PBG being forbidden from propagating in the PC on the grounds of Bragg diffraction and scattering [37,38]. Slow light effect means that the group velocity of photons would be reduced when trying to penetrate the PC structure, giving the photocatalyst more time to make use of the photons [39].…”