Real-Time Phase-Only Spatial Light Modulators for 2D Holographic Display

The use of a distributed representation of a 2D image, such as the complex Fourier transform, has an advantage in image projection due to the inherent fault-tolerant attributes. For example, pixel failures in high-complexity display devices do not appear in the projected image, due to the Fourier transform relationship between the display and the image. It would appear that, in order to represent the Fourier transform of an image, the display device should be capable of fully complex modulation. However, a very good phase-only approximation to the true full complex modulation can be derived by using iterative algorithms, so that phase-modulating spatial light modulators can be employed. This article catalogues a representative selection of devices which have been employed and discusses their relative merits.