Xi'an Institute of Optics and Fine Mechanics has made significant progress in attosecond imaging research

Recently, the Xi'an Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences has made significant progress in attosecond imaging research, achieving high-resolution imaging of ultra wide spectrum light sources. The related results were published in the journal Photonics Research under the title "Snapshot coherent diffraction imaging across ultra wideband spectra".

Figure 1. Demonstration of multi-color diffraction. (a) Diffraction setting. (b) Example image. (c) FT of (b). (d) Obtained through zero padding around (b). (e) FT of (d). (f) Obtain (e) through cropping.

The duration of attosecond light pulses is extremely short (1 attosecond=10-18 seconds), which is a direct and effective means to expand the study of ultrafast dynamics of microscopic matter and reveal underlying physical laws in multiple fields. The attosecond light pulse can achieve ultra-high time resolution, while also possessing characteristics such as short wavelength, high coherence, and high-precision synchronous control. However, the inherent ultra wide spectrum of attosecond light pulses introduces significant chromatic aberration in imaging systems, and the interference between different spectral components and the lack of high-quality optical components in the extreme ultraviolet/soft X-ray band have become bottlenecks restricting the development of attosecond imaging. Our goal is to overcome these technological challenges, achieve ultra-high spatiotemporal resolution imaging based on attosecond light sources, and promote the application of attosecond light sources in fields such as biomedicine, laser precision processing, and semiconductors, "said Wang Hushan, head of the attosecond imaging research team at the attosecond Science and Technology Research Center.

The new method for calculating imaging using lensless ultra wide spectrum proposed by the research team of Xi'an Institute of Optics and Fine Mechanics can extract high-quality clear monochromatic diffraction patterns from blurry ultra wide spectrum diffraction patterns, thereby achieving high-resolution imaging. This method significantly improves the applicable spectral bandwidth of a single coherent diffraction imaging light source, with a spectral bandwidth to center wavelength ratio of up to 140%, which is currently a relatively advanced level internationally, "said Li Boyang, a member of the Amis Imaging Research Team at the Amis Science and Technology Research Center. This study provides a key technological path for attosecond imaging, which is of great significance for the construction of advanced attosecond laser facilities (part of Xi'an) imaging terminals and the significant application expansion of attosecond light sources in China's major scientific and technological infrastructure.

Figure 2. (a) (d) Narrow band coherent diffraction imaging; (b) (e) Direct inversion results of broadband optical diffraction patterns; (c) (f) Broadband coherent diffraction imaging achieved by the monochromatization method proposed by the team

The 2023 Nobel Prize in Physics is awarded to three scientists in recognition of their experimental method of generating attosecond light pulses for studying the electronic dynamics of matter. Fu Yuxi, Deputy Director of Xi'an Institute of Optics and Fine Mechanics, introduced, "Since our establishment, we have had a solid theoretical research foundation in the field of ultrafast light science. In recent years, we have deployed fundamental, forward-looking, and systematic research in the field of ultrafast light science. In 2021, we specifically established the Ames Science and Technology Research Center, closely focusing on the forefront of world science and technology and major national needs, striving to build an international first-class innovative research platform and talent team, and providing key support for seizing the high ground in the field of ultrafast light science.

Source: Opticsky