Methods and systems of creating a photo-mask to form continuous relief micro-structures in photo-active material. This technology uses a basic amplitude mask or electron-beam to create a binary phase grating with pi-phase depth on a transparent reticle coated with photo-active material. The reticle is then used as a phase mask for the fabrication of analog micro-elements. The mask is used in an image reduction machine such as an optical stepper. The period and duty cycle of the phase gratings can be varied to create the proper analog intensity for the desired micro-profile on the photo-active material. The design, analysis, and fabrication procedure of this invention for prisms and positive micro-lenses has been demonstrated.