Abstract: Fabrication of arbitrary profile micro-optical structures (lenses, gratings, etc.) and, if desired, with optomechanical alignment marks simultaneously during fabrication is based upon the use of low-contrast photosensitive material that, when exposed to a spatially variable energy dosage of electromagnetic radiation, can be processed to achieve multi-level or continuous surface-relief microstructures. By varying the exposure dose spatially based upon predetermined contrast curves of the photosensitive material, arbitrary one-dimensional (1-D) or two-dimensional (2-D) surface contours, including spherical, aspherical, toroidal, hyperbolic, parabolic, and ellipsoidal, can be achieved with surface sags greater than 15 &mgr;m. Surface profiles with advanced phase correction terms (e.g., Zernike polynomials) can be added to increase the alignment tolerance and overall system performance of the fabricated structure can also be fabricated.