Fabrication of diffractive optical elements with arbitrary surface-relief profile by direct laser writing

A new method is developed to precisely control the key parameters for fabricating high quality diffractive optical elements with any surface-relief profiles. For the case of direct laser writing on photoresists these parameters include the laser intensity, laser writing speed, etc. A computer control system has been programmed to compute the corresponding laser intensity incremental step and the spacing of adjacent scans and control of the optimized process for fabricating diffractive optical elements. The compensation due to the laser variation over time has also been considered in the program. An example of a fabricated diffractive optical element and its optical performance is also demonstrated. (C) 2002 Society of Photo-Optical Instrumentation Engineers.