Excitation of vacuum ultraviolet absorption band of SiOH groups by F-2 excimer laser photons (7.9 eV) was performed for synthetic SiO2 glasses. Irradiation induced two concurrent optical changes; red-shift of SiOH infrared absorption band and bleaching of vacuum ultraviolet absorption edge which is primarily controlled by SiOH absorption. These optical changes have the same origin, that is, the structural alternation of SiOH from isolated to metastable hydrogen-bonded states. The F-2-induced hydrogen-bonded state was thermally stable to similar to 300 degreesC and the kinetic barrier for the thermal relaxation was similar to1.7 eV. The formation of hydrogen-bonded state proceeded via one-photon absorption processes for F-2 laser irradiation, but did not occur for ArF laser (6.4 eV) irradiation. This F-2-induced hydrogen-bonded state is distinguished from laser-induced compacted state because the latter occurs for ArF or F-2 laser irradiations via two-photon absorption processes.