In a study recently published in the Journal of Synchrotron Radiation, Osaka University, the Japan Institute of Physics and Chemistry, and the Japan Synchrotron Radiation Institute worked together to reduce the beam diameter of the X-ray free electron laser pointer to 6 nanometers. This greatly improves the effectiveness of these laser pointers in the imaging structure, which is closer to the atomic level than the imaging structures in previous work.
In order to "see" extremely small and invisible objects and observe ultrafast chemical processes, researchers usually use synchrotron X-ray equipment. In principle, the X-ray free electron laser is an alternative, which can image atomic-scale details on the time scale of the electronic leap without damaging the particles. To do this, you need a very bright X-ray laser that can focus very fast laser pulses on the nanometer scale.
The first author of the study Takato Inoue said: "Using a multilayer focusing lens, we reduced the width of the laser beam to a diameter of 6 nanometers, which is not the diameter of a typical atom, but we are making good progress."
So far, it is difficult for X-ray free electron lasers to focus to such a small diameter. This is because there are challenges in manufacturing the required mirrors and determining the focus size of the laser. The research team solved the focus problem by analyzing the shape of the laser interferogram, the so-called speckle profile.
The researchers stated that they generate speckle profiles through coherent X-ray scattering of randomly distributed metal nanoparticles. Finally, the green laser pointer beam profile measured by the experiment agrees with the theoretical calculation.
Researchers predict that ultra-high-intensity laser pointers will be used to image ultra-fast molecular processes-details on the atomic scale-which exceed the capabilities of the most advanced synchrotrons. With this technology, under the strategy of "diffract first and then destroy", only one laser pulse can be used to image protein molecules and other important small biological entities without damaging them.