Imaging and Display of Human Size Scenes by Long Wavelength Digital Holography

In this chapter it is shown how the imaging of human size object as well as live people through smoke and flame curtains is possible thanks to the infrared digital holography (IRDH). This technique exploits the advantages of the long infrared wavelength source, i.e. low sensitivity to seismic noise and large field of view capability, and those of the digital holographic technique, i.e. lensless acquisition and discharge of non-coherent radiation, allowing to see through flames, also in outdoor conditions. The acquired holograms can be numerically or optically reconstructed. In the first case, the image is shown on a computer display, while in the second case a visible laser source and some spatial light modulators are used to project the image on a screen or to obtain a floating in space object reproduction.