A novel source of time‐varying losses in electron‐beam‐pumped GaAs lasers is described. Over the range of electron‐beam voltages typically employed in such lasers, this loss initially greatly exceeds that due to reflectivity losses at the cavity end faces. This loss is predicted to fall off rather dramatically as a function of time after the start of the pumping pulse. Such a dynamic loss has a number of consequences. In particular, it leads to a source of faster‐than‐band‐gap wavelength tuning of the laser emission through an effect somewhat akin to the inverse of a dynamic Burstein shift.