In this work, we have studied the possibility of modulating the time-v
arying dipole moment of excitons in an asymmetric double quantum well
system through an external applied magnetic field. In this way, a tuna
ble terahertz radiation emerging from the coupled quantum wells is obt
ained. The magnetic field direction is perpendicular to the double-wel
l heterostructure growth axis obtaining a significance field-effect on
the device for small B values.