This overview covers most of the 3-D displays that are in use today and presents recent developments and advances in this field.

After the invention of lasers, in the past 50 years progress made in laser-based display technology has been very promising, with commercial products awaiting release to the mass market. Compact laser systems, such as edge-emitting diodes, vertical-cavity surface-emitting lasers, and optically pumped semiconductor lasers, are suitable candidates for laser-based displays. Laser speckle is an important concern, as it degrades image quality. Typically, one or multiple speckle reduction techniques are employed in laser displays to reduce speckle contrast. Likewise, laser safety issues need to be carefully evaluated in designing laser displays under different usage scenarios. Laser beam shaping using refractive and diffractive components is an integral part of laser displays, and the requirements depend on the source specifications, modulation technique, and the scanning method being employed in the display. A variety of laser-based displays have been reported, and many products such as pico projectors and laser televisions are commercially available already.

Core/shell nanocrystal quantum dots (NQDs) have shown great potential as efficient electroluminescent materials in devices like down-conversion phosphors and light-emitting diodes (LEDs). The efficiency of these devices is nonlinearly enhanced by the use of high quantum yield (QY) materials. Though relatively high QY materials with inherent advantages for use in device applications are achieved by thick-shell CdSe/CdS NQDs, their QY is not anywhere near unity due to lack of correlation of the microstructure with their photophysical properties. Here, in this Letter, we show that the control of interfacial defects is crucial to achieve a near-unity QY using microstructure studies of CdSe/CdS NQDs. Simple unoptimized LEDs obtained from these NQDs as the active layer demonstrate performances in excess of 7000 Cd/m 2 with a power conversion efficiency of ∼1.5 lm/W that is comparable to those of the best NQD-based LEDs (1−3%) despite the absence of an electron-injecting buffer layer. SECTION: Physical Processes in Nanomaterials and Nanostructures

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These studies show that oxolane-chitosan-polyurethane (OXO-CHI-PUR) networks exhibit selfrepairing behavior upon exposure to UV light. Spectroscopic analysis revealed that molecular level processes responsible for the self-repairing mechanism of OXO-CHI-PUR networks are driven by free radical catalyzed polyurea-to-polyurethane conversion, formation of linear -C-O-C-segments via ring opening of OXO rings, as well as chair-to-boat conformational changes of glycosine units of the CHI backbone macromonomer. Incorporation of the OXO five-member ring instead of OXE (fourmember) into polyurethane networks facilitates slower but equally effective self-healing characteristics. The role of protic conditions inside the scratch showed that highly acidic environments favor scratch expansions instead of self-healing. Similar to self-healing of OXE-CHI-PUR networks, as a result of mechanical damage, glass transition temperature (T g ) is lowered within the damaged area, resulting in the formation of smaller macromolecular oligomeric entities with enhanced mobility. The repair mechanisms measured by the thermo-mechanical response inside and outside the scratch showed that upon UV light exposure the damaged area is repaired by the frontal growth reactions from the bottom of the scratch to the top, and the mass flow is facilitated by the lower glass transition temperature (T g ) inside the scratch. These studies also show that the presence of hindered amine light stabilizers (HALSs) retards self-healing, which can be compensated by elevated levels of the OXO component in OXO-CHI-PUR networks.