Generation of diffractive optical elements onto a photopolymer using a liquid crystal display [7717-12]

Liquid crystal displays (LCDs) are widely used as spatial light modulators (SLMs) in many applications (optical signal processing, holographic data storage, diffractive optics...). In particular, as an alternative microoptics recording scheme we have explored the possibility to use a LCD to display the diffractive optical element (DOE) to be recorded onto a photosensitive phase material, so as to enhance the flexibility of the recording architecture. In this application the LCD acts as an amplitude dynamic transparency. By means of an optical system we image the function addressed to the LCD onto the recording material. The element to be recorded onto the phase material can be easily changed simply by changing the function addressed to the LCD. Among the recording materials, photopolymers provide very attractive capabilities. They present a great flexibility in their composition, the recording layer can be manufactured in a wide range of possible thicknesses, and they are inexpensive. These properties make it an interesting material to generate the phase DOEs. Both the composition and the thickness need to be optimized for the application to DOEs. In this work we explore the results dealing with the calibration of the recording setup and the photopolymer material. We also analyse the performance of phase-only diffractive lenses generated onto the photopolymer. Promising results have been obtained, where the focalization of the diffractive lenses generated has been demonstrated.