Design of multiaperture masks for subnanometer correction of ultraprecision optical components

A technique for correction of optical surfaces has recently been reported. The technique involves oscillating an optical surface back and forth behind a multiaperture mask to deposit a spatially varying dielectric layer onto the optic to create the desired surface profile. Details are reported of a modified mask design that inherently smooths the deposited layer used for these corrections. Results are also reported with regard to a recent correction that resulted in a thickness uniformity of better than lambda/2000 rms over a working aperture of 37.5 mm.