Woofer-tweeter control in an adaptive optics system using a Fourier reconstructor

Future adaptive optics systems seeking a higher degree of correction may need to split the command between two deformable mirrors (DMs), the woofer and the tweeter. We first present a method to specify the order of correction of the woofer DM for a given tweeter stroke requirement using an analytical and Monte Carlo;approach. We then develop a computationally efficient algorithm to split the command between the two DMs in the case where a Fourier reconstructor is used. We find that the computational efficiency can be dramatically improved by splitting the command in Fourier space and by sending to the woofer only the modes it can reproduce accurately. (C) 2008 Optical Society of America.