Holographic fabrication of multiple layers of grating inside soda–lime glass with femtosecond laser pulses

Gratings have been holographically fabricated inside soda–lime glass by two-beam interference of a single 130 fs laser pulse at a wavelength of 800 nm. Because the grating was localized in the focal volume and the depth at which the grating was formed can be controlled by translation of the sample, multiple layers of grating can be fabricated. As an example, three layers of grating have been recorded at depths of ∼200, ∼400, and ∼600 μm, respectively. These gratings can be read by either of the two recording beams with reduced energy, which demonstrates their potential applications in integrated optics and optical storage.