OPTICAL SWITCHING AND HIGH-RESOLUTION IMAGE TRANSFER IN A SATURABLE DYE SPATIAL LIGHT-MODULATOR

We experimentally demonstrate and theoretically analyze practical aspects of using a laser-pumped dye medium as an ultrafast (similar to 10-ps) optically addressed spatial light modulator for application with high-power radiation. Optical modulation of the absorption of a high-power pump beam is produced by a relatively weak (control) beam that is experiencing stimulated emission. The intensity of the control beam required for strong switching of the pump-beam transmission is determined by the gain that is due to stimulated emission at the control-beam frequency. A practical limitation on the gain that is due to excited-state absorption of the pump frequency is described. We demonstrate the application of the dye medium spatial light modulator for high-resolution image transfer and determine the resolution limit of the transfer process. Experimental demonstration is made of optical image processing (edge enhancement). The control beam can also be generated by self-lasing in feedback geometries, and pump transmission can be controlled by the strength of the feedback.