<title>Fabrication and optical characteristics of microlens arrays engraved in photoresist coatings</title>

Abstract

We have developed a technique for fabricating microlens arrays by engraving photoresist coatings. These microlens arrays are designed for astronomical applications for atmospheric wavefront sensors.First, we describe the apparatus and the manufacturing proce. Sond, we review the characteristics of the different pbotoresist types used in this process. Third, we report on the different optical testing methods to nasure the microlens'performances. Then we deduce the several inherent advantages and limitations of this method.Forth we show bow to produce monolithic arrays using ion beam milling with photoresist inicrolens arrays as pattern and we demonstrate how these arrays can improve upon the performances of photoresist arrays.In conclusion, we point out the advantages and limitations of photoresist microlens arrays and the applications for which they are most suited. 0-81 94-0960-X/93/$4.00 SPIE Vol. 1781 Specification and Measurement ofOptical Systems (1992) / 287 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/25/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

Fabrication of a gray-tone mask and pattern transfer in thick photoresists

“…According to the application, this pattern is either the final structure or is used as a mask or a mould in order to be transferred by selective electrodeposition or reactive ion etching into the appropriate material (quartz substrate for example) [1,2]. There are several methods of fabricating the mask which predetermines the surface topography [1][2][3][4][5][6][7][8][9][10]. To reduce the cost of fabrication, O'Shea and Rockward [3] proposed a new process using a high-resolution image setter to elaborate a primary mask.…”