A beam control system and method. The system includes an illuminator for providing a first beam of electromagnetic energy at a first wavelength; a source for providing a second beam of electromagnetic energy at a second wavelength; and an arrangement for compensating wavefront errors in the second beam using a bias representative of a comparison between the first wavelength and the second wavelength. In the illustrative embodiment, the arrangement includes a processor which corrects wavefront errors using a bias representative of a difference between said first wavelength and said second wavelength. In the disclosed application, a target wavefront sensor is included and the laser is a high-energy laser beam. The wavefront errors include a chromatic aberration and the errors are compensated using a deformable mirror and a correction algorithm executed by an adaptive optics processor. In one alternative embodiment, the errors are compensated using an optical aberration corrector. The aberration corrector may be a holographic optical element or other suitable device. In another alternative embodiment, the errors are corrected with the above embodiment in combination with the use of "woofer" and "tweeter" correcting elements with the woofer being a long stroke low frequency element and the tweeter being a short stroke high frequency element.