Fig. 5
Patterned FP etalon on transparent substrate for H2 leakage warning display. a, b Schematic layer description (a) and photograph (b) of 12 fabricated f-etalon samples on glass substrate. c Photographs of the sample with Ag top film displaying color variation in response to different gas composition. d Angle-dependent color variation and foggy effect under H2 exposure. e, f Scheme of f-etalon on glass applied for H2 leakage warning window (e) and its demonstration in a miniaturized H2 storage facility (f). Scale bars, 1 cm