systems u201d by n c macdonald and gray scale as described in article u201c cost effective mass fabrication of multilevel diffractive optical elements by use of a single optical exposure with a gray scale mask on high energy beam sensitive glass u201d by w daschner p long r stein c wu s h lee can be used to design all terahertz optical components as kinoform optics for terahertz frequencies in mid range 500 to 5000 ghz the structure could be produced by x ray lithography using liga based har process as described in article u201c production of separation nozzle systems for uranium enrichment by a combination of x ray lithography and galvanoplastics u201d by e w becker w ehrfeld d munchmeyer h betz a heuberger s pongratz w glashauser h j michel r von siemens for the disclosed method and apparatus a terahertz wave of 5000 ghz almost at the middle of the terahertz frequency band and rexolite material for substrate is selected rexolite has refractive index of 1 59 and has relative low absorption in selected frequency band we calculated the device structure to show the dimensions that could fit in a size of moem chip similar calculation can be used for optical processing of terahertz imaging system in all terahertz bands the substrate is preferably selected to have low absorption and relatively larger index of refraction in lower than 5000 ghz frequencies the device sizes become larger that makes them impractical to be processed by standard icp process and moems technology in some cases where the terahertz frequency is much lower less than 500 ghz use of computer numerical control cnc and mechanically machining the structure is preferred after the.