A self-trapped filament of ultrashort laser pulses can induce a 10–500 µm-long region of refractive-index change in silica glass. The translation of filament perpendicular to the optical axis induces a layer of refractive-index change with a thickness of 2 µm. We stacked the layers periodically and fabricated volume gratings. We irradiated a He–Ne laser beam at the wavelength of 632.8 nm onto the gratings at the Bragg angle. The maximum diffraction efficiency was 74.8% with the grating that had the period of 3 µm and the thickness of 150 µm.