Design and characteristics of holographic neural photo-stimulation systems.

Computer-generated holography is an emerging technology for stimulation of neuronal populations with light patterns. A holographic photo-stimulation system may be designed as a powerful research tool or a compact neural interface medical device, such as an optical retinal prosthesis. We present here an overview of the main design issues including the choice of holographic device, field-of-view, resolution, physical size, generation of two- and three-dimensional patterns and their diffraction efficiency, choice of algorithms and computational effort. The performance and characteristics of a holographic pattern stimulation system with kHz frame rates are demonstrated using experimental recordings from isolated retinas.