biostudies-literature00640Mao YNational Natural Science Foundation of ChinaNational Natural Science Foundation of China (National Science Foundation of China)22https://www.ebi.ac.uk/biostudies/studies/S-EPMC7820001biostudies-literatureUnknown10(1)Vacuum ultraviolet (VUV) lasers have demonstrated great potential as the light source for various spectroscopies, which, if they can be focused into a small beam spot, will not only allow investigation of mesoscopic materials and structures but also find application in the manufacture of nano-objects with excellent precision. In this work, we report the construction of a 177 nm VUV laser that can achieve a record-small (~0.76 μm) focal spot at a long focal length (~45 mm) by using a flat lens without spherical aberration. The size of the beam spot of this VUV laser was tested using a metal grating and exfoliated graphene flakes, and we demonstrated its application in a fluorescence spectroscopy study on pure and Tm³⁺-doped NaYF₄ microcrystals, revealing a new emission band that cannot be observed in the traditional up-conversion process. In addition, this laser system would be an ideal light source for spatially and angle-resolved photoemission spectroscopy.Light, science & applicationsA vacuum ultraviolet laser with a submicrometer spot for spatially resolved photoemission spectroscopy.PMC7820001117741901177442761705085Li JHan KYang LZhang HYan SHuang KChen YZhao DGuo CXu XZhang CMao Y64falseA vacuum ultraviolet laser with a submicrometer spot for spatially resolved photoemission spectroscopy.Vacuum ultraviolet (VUV) lasers have demonstrated great potential as the light source for various spectroscopies, which, if they can be focused into a small beam spot, will not only allow investigation of mesoscopic materials and structures but also find application in the manufacture of nano-objects with excellent precision. In this work, we report the construction of a 177 nm VUV laser that can achieve a record-small (~0.76 μm) focal spot at a long focal length (~45 mm) by using a flat lens without spherical aberration. The size of the beam spot of this VUV laser was tested using a metal grating and exfoliated graphene flakes, and we demonstrated its application in a fluorescence spectroscopy study on pure and Tm³⁺-doped NaYF₄ microcrystals, revealing a new emission band that cannot be observed in the traditional up-conversion process. In addition, this laser system would be an ideal light source for spatially and angle-resolved photoemission spectroscopy.2021-01-01T00:00:00Z2021 Jan2024-11-11T20:06:14.5Z2021-02-21T04:33:58ZS-EPMC78200013347919210.1038/s41377-021-00463-3