A simple low resolution volumetric display is presented, based on holographic volume-segments. The display system
comprises a proprietary holographic screen, laser projector, associated optics plus a control unit. The holographic screen
resembles a sheet of frosted glass about A4 in size (20x30cm). The holographic screen is rear-illuminated by the laser
projector, which is in turn driven by the controller, to produce simple 3D images that appear outside the plane of the
screen. A series of spatially multiplexed and interleaved interference patterns are pre-encoded across the surface of the
holographic screen. Each illumination pattern is capable of reconstructing a single holographic volume-segment. Up to
nine holograms are multiplexed on the holographic screen in a variety of configurations including a series of numeric
and segmented digits. The demonstrator has good results under laboratory conditions with moving colour 3D images in
front of or behind the holographic screen.
Pump-probe femtosecond transmission measurements in the vicinity of the first excitonic resonance are performed in a silicate glass embedded with Cd-S-Se semiconductor nanoparticles. In the experiment, the pump at 400 nm (duration 50 fs, energy up to 0.1 mJ) excites the sample, while the change of the optical absorption is probed by femtosecond continuum. The time-resolved spectrum of the absorption change in the wavelength range 450-650 nm is visualized using a two-channel imaging spectrometer. A strong optical nonlinearity of the glass containing Cd-S-Se nanoparticles results in the up to 50% bleaching of the first excitonic resonance via the depopulating of the ground state. The temporal evolution of the bleaching consists of fast (with relaxation time as small as 3 ps) and slow (>15 ps) components. The dependence of the nonlinear absorption on the detuning of the pump and probe wavelengths with respect to the exciton resonance is evaluated.