We present a theoretical investigation of a novel staircase-like light emitter based on the GaAs/GaxAl1-xAs material system. The emission wavelength is around 12 mum. The device operation is based on the intersubband bound-to-bound transition. The energy band profile of the structure has been solved self-consistently. We have also calculated the oscillator strength. (C) 2004 Elsevier Ltd. All rights reserved.