Luminescent Cavity Design for High Ambient Contrast Ratio, High Efficiency Displays

A key display characteristic is its efficiency (emitted light power divided by input power). While display efficiencies are being improved through emissive (e.g., quantum dot and organic light emitting display (OLED) designs1,2, which remove the highly inefficient color filters found in traditional liquid crystal displays (LCDs)3,4, polarization filters, which block about 50% of the light, remain required to inhibit ambient light reflection. We introduce a luminescent cavity design to replace both the color and polarization filters. Narrow-band, large Stokes shift, CdSe/CdS quantum dot emitters are embedded in a reflective cavity pixel element with a small top aperture. The remainder of the top surface is coated black reducing ambient light reflection. A single pixel demonstrates an extraction efficiency of 40.9% from a cavity with an 11% aperture opening. A simple proof-of-concept multi-pixel array is demonstrated.

High-Efficiency Mini-Slab Laser Based on Tm-doped Double Tungstate Crystal

We report on highly-efficient room-temperature lasing in 5at.%Tm:KLu(WO4)2 mini-slabs side-pumped by a 35W diode bar. QCW (duty cycle ∼ 14%) output power of 1.47 W at 1908 nm has been demonstrated with optical and slope efficiencies being of 33 and 43% respectively. In our experiments, we used samples of active elements produced in the slabs form with Brewster’s angle cut faces and original laser cavity design.

R&D of CEPC injector linac

The CEPC includes a main ring and an injector. The injector consists of a booster and a linac. In order to meet the requirements of the booster, the baseline design of the linac is a 10 GeV electron and positron linac. Two alternative linac designs have also been introduced in this paper. For the linac baseline design, one-bunch-per-pulse is adopted. A 1.1 GeV damping ring is used to reduce the transverse emittance of positron beam. The main RF system of the linac adopts normal conducting S-band structure. Some key technologies of linac are development. The S-band structure and pulse compressor have been researched and studied. In the damping ring, two cavities used to provide 2 MV voltage. The preliminary cavity design has finished.