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We have observed the emission spectra of three-dimensional Rayleigh-Fabry-Perot cavity whispering-gallery modes from photonic quantum ring lasers that give rise to uniform angular mode spacing in space. The observed angular distribution (0[degrees] [tilde] 30[degrees]) of the emission modes is linear with respect to the mode number. For example, the average angular mode spacing is 0.95[degrees] with a standard deviation of 0.098[degrees] for a 20-[micro]m-diameter laser, whose potential angle-resolving power is promising for angle-sensing applications in the future. OCIS codes: 140.5960, 280.3420.

This study examines the catch-up experiences of the Chinese game industry from a neo-Schumpeterian perspective. It determines that Chinese indigenous firms succeeded in catch-up by strategically responding to favourable policy changes, such as a quota system that limited the import of overseas games and content inspection by the government. It is found that China has established its capabilities in a quite different manner than the experience of advanced countries during the dynamic catch-up process. This verdict shows that the order of capability development of late-comer countries can be different from that of advanced countries. Despite numerous studies that emphasise the role of government, we argue that, even when the market is unsegmented, if foreign knowledge is accessible, then the necessary intervention can involve little more than the protection of the initial market in the form of exclusive licensing, import restriction, not sharing R&D costs or promoting marketing activity. Despite exclusive licensing, import restriction and piracy, overseas game firms continued co-operating with China in the form of a publishing contract and IP sales due to massive market opportunities in China. This indicates that a large country with an immense domestic market can differentiate its catch-up strategies from those of small-market countries. [ABSTRACT FROM AUTHOR]

We investigate the effect of the properties of an intracavity diamond heat spreader on the lasing performance of vertical-external-cavity surface-emitting lasers. We compared two intracavity diamonds with different average birefringences. When a polarization selective element is inserted into the cavity, the infrared output powers are reduced by 13% and 7%, respectively, for the samples with higher and lower average birefringences. The pump-power limited maximum green output powers were changed from 3 to 5.2 W by rotating the samples with lower average birefringence. In order to explain the variation in green output power, the additional round-trip loss caused by diamond birefringence was analyzed theoretically and experimentally. We found that the loss can be reduced when axes of the birefringence are aligned to the axes of the polarization selective element. [ABSTRACT FROM AUTHOR]

We report on the demonstration of highly efficient blue lasers based on intracavity frequency doubling vertical-external-cavity surface-emitting lasers (VECSELs). By optimizing the number of InGaAs quantum wells and employing Al0.3Ga0.7As carrier blocking layers in resonant periodic gain structures, we observed the pump-power-limited output power of 4.5 W at 920 nm for an InGaAs/GaAs quantum well VECSEL. With a frequency doubling LiB3O5 crystal inside the cavity, 1.9 W continuous-wave 460 nm blue output was demonstrated. Power conversion efficiencies (=output power/pump input power) of 22.5% and 9.5% are realized for λ∼920 nm and λ∼460 nm, respectively. [ABSTRACT FROM AUTHOR]

Highlights: [•] Correlations between carrier dynamics and structural defects of InGaN MQWs exist. [•] PL intensity is much weaker in the V-shaped pits than in the regular c-plane. [•] Blue-shifted photoluminescence spectrum is not observed at the V-pits. [•] A kinetic model including carriers recombination and diffusion is presented. [•] The model estimates the nonradiative recombination time as 10ps at the V-pits. [ABSTRACT FROM AUTHOR]