Volume plasma grating by noncollinear interaction of femtosecond filament arrays

Stable propagation of multifilament arrays in transparent bulk media with adjustable separation distances between adjacent child filaments has always been desired for advanced manufacturing. Here, we report on the generation of an ionization-induced volume plasma grating (VPG) by the interaction of two batches of noncollinearly propagating arrays of multiple filaments (AMF). The VPG can externally arrange the propagation of the pulses along regular plasma waveguides via spatial reconstruction of electrical fields, which is compared with the self-formation of randomly distributed multiple filamentation originated from noises. The separation distances of filaments in VPG are controllable by readily changing the crossing angle of the excitation beams. In addition, an innovative method to efficiently fabricate multidimensional grating structures in transparent bulk media through laser modification using VPG was demonstrated.