For different applied magnetic fields, the intersubband transitions of double Si delta-doped GaAs structures is theoretically investigated for a uniform donor distribution. The electronic structure has been calculated by solving the Schrodinger and Poisson equations self-consistently. It is found that the intersubband optical absorption and mobility are sensitive to the applied magnetic field: for all allowed intersubband transitions the intersubband absorption spectra show blueshifts. The results open the possibility to design devices for use as optical filters controlled by an applied magnetic field, depending on the delta-doped structure. It is hoped that these results will provide important improvement in device applications, for a suitable choice of magnetic field. (C) 2009 Elsevier Ltd. All rights reserved.