PR_28 Imaging Band-edge Localization in a Silicon Coupled Microring Waveguide (0925133-PO)

Summary of a Project Outcomes report of research funded by the U.S. National Science Foundation under project number 1201308. Silicon microring resonators with resonances in the O band and C band were designed, fabricated and measured.

PR_27 Imaging Band-edge Localization in a Silicon Coupled Microring Waveguide (0925133-PO)

The band-edge localization of light in a coupled resonator optical waveguide (CROW) consisting of silicon microring resonators is studied theoretically and experimentally. Summary of a Project Outcomes report of research funded by the National Science Foundation under Project Number 0925133.

Two-dimensional CdS/SnS2 heterostructure: A highly direct efficient Z-scheme water splitting photocatalyst

A desired water splitting photocatalyst should not only possess suitable bandgap and band edge position, but also host the spontaneous progress for overall water splitting without the aid of any...

Transient reshaping of intraband transitions by hot electrons

Hot electrons transiently redshift intraband transitions of colloidal quantum wells when electrons are excited above the band edge.

Effect of Mn2+ incorporation on the photoelectrochemical properties of BiVO4

BiVO4 is a promising photoanode material for photoelectrochemical water splitting applications due to its narrow band gap i.e., ̴ 2.4 eV, suitable band-edge positions, non-toxicity and high stability. Here, we...

Compact, flexible and highly selective wideband complementary FSS with high angular stability

This article presents a novel miniaturized (0.105λ0 × 0.105λ0) flexible complementary frequency selective surfaces (CFSS) structure with sharp band edge selectivity and very high angular stability. To explore two diverse applications as a passband and stopband filter, a novel complementary convoluted square loop (CCSL) type structure has been designed and investigated on ultrathin dielectric material of thickness 0.0023λ0. The second-order wide controllable passband with fractional bandwidth of 19.23% (−3 dB) and remarkably wide stopband of 64.7% (−10 dB) and 54.8% (−20 dB) respectively have been achieved by using a cascaded resonating structure which is composed of asymmetrical meandered CCSL array, arranged on two ultrathin dielectric layers with air foam separation. This particular format would lead to sharp band edge selectivity with steep roll-off (72.43 dB/GHz) and an excellent passband selectivity factor (0.731). An equivalent lumped LC circuit in conjunction with the transmission line model has also been adopted to comprehend the physical mechanism of the proposed single layer and double layer structures. Further, better passband and stopband angular stability at an oblique incident angle of 45° and the bending characteristics have also been investigated thoroughly for the proposed flexible CFSS to check their employability in different conformal structures with WiMAX passband and WLAN stopband application.

Monolithically integrated green-to-orange color InGaN-based nanocolumn photonic crystal LEDs with directional radiation beam profiles

In this study, the monolithic integration of LEDs with different emission colors (wavelengths of 543, 573, and 597 nm) with the directional radiation profiles was demonstrated. InGaN/GaN nanocolumn arrays ordered in a triangular lattice were prepared side by side, changing the diameter of the n-GaN nanocolumn (Dn-GaN). The periodic arrangement of the nanocolumns led to the photonic crystal (PC) effect. The photonic band edge wavelength (λB) and the InGaN bandgap were controlled by the Dn-GaN. By controlling λB closely at the bandgap wavelength, the PC effect provided directional beam radiation from the LEDs with radiation angles of approximately ±30°