  We study the role of the inter- and intraband current in the laser
interaction with the bi-chromatic quasi-periodic crystals. The interaction
dynamics are simulated by solving the time-dependent Schr\"odinger equation in
the $k$-space, and time evolution of the inter- and intraband current is
obtained in a gauge invariant form. We observed that for certain bi-chromatic
potential ratios, the energy band structure of the `valence band' and the
`conduction band' facilitate the interband transitions only at the center or at
the edge of the Brillouin zone, which leads to a very interesting population
transfer mechanism between the bands. The temporal profile of the inter- and
intraband current gives a detailed account of the interaction. The higher-order
harmonic generation (HHG) is also studied for these bi-chromatic optical
lattices, and the resultant harmonic yield is commented upon.
