<title>New challenges for spatial light modulators: laser beam splitting and beam shaping, and reconstruction of digital holograms</title>

Abstract

Liquid crystal displays, operating in a linearized phase mode, can achieve a performance to be applicable as diffractive elements. We built up a Fourier-system with a Sony-LCD based spatial light modulator in order to realize dynamic diffraction patterns. The quality measures of our DOE in the output plane of the system are promising for a wide range of applications. The performance oftechnical beam splitters, realized as binary or 8-256 level diffractive elements will be discussed in the paper. Here we will focus on parameters as diffraction efficiency, signal to noise ratio and also speckle effects. Since the display is addressed directly from the graphics card series of diffraction patterns and animations can be realized. Furthermore, beam shaping elements, two-dimensional holograms and the reconstruction of digital holograms will be shown. The latter opens new possibilities for non-destructive testing devices especially in the field of holographic interferometry. The limiting parameters of the performance are mostly due to physical boundary conditions, such as pixel number and size, response time, transmission etc. . We can assume that the fast growing micro-structuring technology will serve us soon with displays of higher resolutions and efficiency. A discussion concerning requirements for medial or micro-fabrication applications, particularly due to the limited efficiency and the intensity-dependent modulation, will finish the paper.