ABSTRACT
An electrically controlled holographic switch is proposed as a building block for a free-space optical interconnection network. The switch is based on the voltage-controlled photorefractive effect in KLTN crystals at the paraelectric phase. It is built of electrically controlled Bragg gratings stored in the volume of the crystal. A compact switch that connects four high-speed fiber-optic communication channels with high efficiency is demonstrated experimentally. The switch performance is investigated and optimized. This switch is extremely attractive for cascaded switching arrays such as those found in multistage interconnect networks.
ABSTRACT
A new approach to studying the effects of absorption by aerosols and molecular particulates of electromagnetic radiation is presented. In contradiction to the conventional concept that absorption gives rise to constant attenuation, it is shown here that the particulate-absorbed irradiance is spatial frequency dependent. An analytically corrected model of the aerosol modulation transfer function and the aerosol mutual coherence function is presented. An important application of this model is in thermal imaging, in which particulate-absorption effects are very significant.
