Quantum dot vertical-cavity surface-emitting lasers covering the 'green gap'.

Semiconductor vertical-cavity surface-emitting lasers (VCSELs) with wavelengths from 491.8 to 565.7 nm, covering most of the 'green gap', are demonstrated.

Rigorous microlens design using vector electromagnetic method combined with simulated annealing optimization.

In this paper, finite-aperture diffractive optical element with its critical dimension smaller than illumination wavelength is modeled and optimized using an integrated method. This method employs rigorous analysis model based on Finite Difference Time Domain (FDTD), and simulated annealing (SA) global search algorithm. Numerical results reveal that the diffraction efficiency of the 8-step microlens quickly climbs to its global optimum along with the optimization process, which manifests its global search ability.

Well-width dependence of the emission linewidth in ZnO/MgZnO quantum wells.

Photoluminescence (PL) spectra were measured as a function of well width (LW) and temperature in ZnO/Mg0.1Zn0.9O single quantum wells (QWs) with graded thickness.

Performance enhancement of GaN-based light emitting diodes by transfer from sapphire to silicon substrate using double-transfer technique.

GaN-based light emitting diodes (LEDs) fabricated on sapphire substrates were successfully transferred onto silicon substrates using a double-transfer technique. Compared with the conventional LEDs on sapphire, the transferred LEDs showed a significant improvement in the light extraction and thermal dissipation, which should be mainly attributed to the removal of sapphire and the good thermal conductivity of silicon substrate. Benefited from the optimized wafer bonding process, the transfer processes had a negligible influence on electrical characteristics of the transferred LEDs.

[Bonding structure in silicon nitride thin films containing silicon nano-particles].

Non-stoichiometric hydrogenated amorphous silicon nitride (a-SiNx : H) film was deposited by helico-wave plasma-enhanced chemical vapour deposition (HWP-CVD) technique. The microstructure and bonding characteristics of both as-deposited and annealed thin films were studied. Raman scattering measurement shows that excess silicon exists in the form of amorphous silicon particles in the as-deposited sample.