Spatial Light Modulator Technology in Optical Computing

The Spatial Light Modulator(SLM) has expanded the realms of optical processing by linking the electrical and optical worlds, allowing the input of image information into the parallelism of the optical processor. This hybrid of digital and optical computers fulfils the speed requirements of two dimensional processing, but is limited by the update speed, and to some extent the cost, of the SLM. We are investigating the use of two types of SLM, the first being the Digital Micro-mirror Device (DMD), and the second, the Liquid Crystal Display (LCD) shown in Figure . By developing methods for driving the LCD directly (see below), rather than relying on a video interface, improved optical performance is obtained. Additionally, we investigate the use of the SLM in an optical system, in particular, the patterns or images that extrapolate the usefulness of the SLM. Programmable diffractive elements, as such are called, provide for the construction of optical systems that may be changed under computer control. The diffractive element displayed on the SLM, may act for example, as a lens of programmable focal length. Such a diffraction pattern is shown in Figure , and is recognised as similar to a Fresnel zone plate. Other such images allow for beam confinement, replica production, and movement of the image formation plane within an optical system.

Please also visit http://www.ee.adfa.edu.au/widearea/ for images related to the above reseach.

Research Activities of the School