Compact gain-saturated x-ray lasers down to 6.85 nm and amplification down to 5.85 nm

Rockwood, Alex, authorWang, Yong, authorWang, Shoujun, authorBerrill, Mark, authorShlyaptsev, Vyacheslav N., authorRocca, Jorge J., authorOptical Society of America, publisher2020-04-282020-04-282018-03-02Alex Rockwood, Yong Wang, Shoujun Wang, Mark Berrill, Vyacheslav N. Shlyaptsev, and Jorge J. Rocca, "Compact gain-saturated x-ray lasers down to 6.85 nm and amplification down to 5.85 nm," Optica 5, 257-262 (2018) https://doi.org/10.1364/OPTICA.5.000257https://hdl.handle.net/10217/206007Plasma-based x-ray lasers allow single-shot nano-scale imaging and other experiments requiring a large number of photons per pulse to be conducted in compact facilities. However, compact repetitively fired gain-saturated x-ray lasers have been limited to wavelengths above λ = 8.85 nm. Here we extend their range to λ = 6.85 nm by transient traveling wave excitation of Ni-like Gd ions in a plasma created with an optimized pre-pulse followed by rapid heating with an intense sub-picosecond pump pulse. Isoelectronic scaling also produced strong lasing at 6.67 nm and 6.11 nm in Ni-like Tb and amplification at 6.41 nm and 5.85 nm in Ni-like Dy. This scaling to shorter wavelengths was obtained by progressively increasing the pump pulse grazing incidence angle to access increased plasma densities. We experimentally demonstrate that the optimum grazing incidence angle increases linearly with atomic number from 17 deg for Z = 42 (Mo) to 43 deg for Z = 66 (Dy). The results will enable applications of sub-7 nm lasers at compact facilities.born digitalarticleseng©2018 Optical Society of America. Under the terms of the OSA Open Access Publishing Agreement. Biomedical Optics Express, Optica, Optical Materials Express, Optics Express, and OSA Continuum are all gold open access journals. As a result of the authors paying an article processing charge (APC), all content published in these journals is freely available.Copyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.x-rayscoherenceamplificationrecoverygainamplifiersmolybdenumlaserslasers, optics, and electronics (so)photonics (general) (ea)optics (ah)Compact gain-saturated x-ray lasers down to 6.85 nm and amplification down to 5.85 nmTexthttps://doi.org/10.1364/OPTICA.5.000257