Comparison of III-V/Si on-chip lasers with etched facet reflectors.

Electrically pumped heterogeneously integrated III-V/SiO semiconductor on-chip lasers with different types of etched facet reflectors are designed and fabricated and their lasing performances are characterized and compared. The III-V quantum-well-based epitaxial layers are bonded on silica-on-silicon substrates and fabricated to form Fabry-Perot lasers with dry-etched rear facets. Three types of reflectors are demonstrated, which are etched facets terminated by air, benzocyclobutene, and metal with a thin layer of SiO insulator in-between.

An Overview of Maxillofacial Trauma in Oral and Maxillofacial Tertiary Trauma Centre, Queen Elizabeth Hospital, Kota Kinabalu, Sabah.

The aims of this study were to provide an overview of maxillofacial trauma and its relationship to patient's demographic data and alcohol consumption within the state of Sabah. It was a retrospective study of maxillofacial trauma cases treated by Oral and Maxillofacial Surgery Department, Queen Elizabeth Hospital, Kota Kinabalu, Sabah, from January 1, 2009, until December 31, 2013. A total of 630 maxillofacial trauma cases were included.

Hetero-core III-V/Si microlaser.

We design and demonstrate optically pumped microlasers with a hetero-core cavity formed by III-V and silicon-on-insulator (SOI) materials. Hetero-core cavities with identical lateral dimension are fabricated. The cavity is formed by III-V layer with thickness of 210 nm on top of SOI layer with thickness of 300 nm via SiO interlayer wafer bonding.

Heterogeneously integrated III-V laser on thin SOI with compact optical vertical interconnect access.

A new heterogeneously integrated III-V/Si laser structure is reported in this report that consists of a III-V ridge waveguide gain section on silicon, III-V/Si optical vertical interconnect accesses (VIAs), and silicon-on-insulator (SOI) nanophotonic waveguide sections. The III-V semiconductor layers are introduced on top of the 300-nm-thick SOI layer through low temperature, plasma-assisted direct wafer-bonding and etched to form a III-V ridge waveguide on silicon as the gain section. The optical VIA is formed by tapering the III-V and the beneath SOI in the same direction with a length of 50 μm for efficient coupling of light down to the 600 nm wide silicon nanophotonic waveguide or vice versa.

Light extraction--a practical consideration for a plasmonic nano-ring laser.

An integrated semiconductor plasmonic nano-ring laser with a connecting output plasmonic waveguide for light extraction is proposed, designed and demonstrated numerically. The maximum light extraction efficiency can be up to 56%. The design was optimized with 2D FDTD and verified with 3D FDTD methods, where close agreement is shown between the two.

Management of blunt traumatic thoracic aorta injuries with endovascular stent-grafts in a tertiary hospital in an urban Asian city.

Background: Thoracic aortic injury from blunt trauma is a life-threatening condition with significant mortality and morbidity with open surgical repair. Endovascular means of treatment is emerging as an attractive and less invasive option. We report our experience with endovascular stent-graft repair for blunt traumatic thoracic aorta injury.

New hope for an old cure: a pilot animal study on selective venesection in attenuating the systemic effects of ischaemic-reperfusion injury.

Introduction: Reperfusion of acutely ischaemic tissue may, paradoxically, lead to systemic complications. This phenomenon is believed to be initiated by humoral factors that have accumulated in the ischaemic tissue. The ancient art of venesection may reduce the load of these mediators at the point of reperfusion.

Surgical management of infected pseudoaneurysms in intravenous drug abusers: single institution experience and a proposed algorithm.

Background: Vascular complications from intravenous drug abuse pose significant challenges to vascular surgeons. No formalized policies have been reached on surgical management of the resultant infected pseudoaneurysm.

Methods: A retrospective review of all patients who underwent surgery for pseudoaneurysms due to chronic intravenous drug abuse from July 2005 to February 2008 was performed.

Argon-plasma-induced InAs/InGaAs/InP quantum dot intermixing.

We report the first study of argon (Ar)-plasma-enhanced intermixing of InAs/InGaAs/InP self-assembled quantum dots (QDs) in an inductively coupled plasma reactive ion etch system. The Ar-plasma exposure creates point defects, which propagate into the QD structure and enhance the intermixing between the QDs and their barrier layers, hence tuning the energy bandgap of the QDs. By optimizing the plasma exposure time and the annealing temperature, we observe (i) a blueshift of 160 nm and an increase in the photoluminescence (PL) intensity of the QD samples immediately after Ar-plasma exposure for 90 s, and (ii) a further increase in the blueshift of 330 nm, accompanied by 2.

High-index-contrast waveguides and devices.

We present a theoretical and experimental study of high-index-contrast waveguides and basic (passive) devices built from them. Several new results are reported, but to be more comprehensive we also review some of our previous results. We focus on a ridge waveguide, whose strong lateral confinement gives it unique properties fundamentally different from the conventional weakly guiding rib waveguides.

Transformation between directional couplers and multi-mode interferometers based on ridge waveguides.

We present a unique comparison of ridge-type directional couplers (DC) and multi-mode interferometers (MMI) in terms of their transformational relationship. The two devices are intimately related as the MMI is derived from the DC. We show for the first time the continuous evolution from the two-mode coupling characteristic of DC to the multimode mixing and interference characteristic of MMI, as the DC is structurally transformed into the MMI.

Polarization-independent vertical coupler for photonics integration.

We present the first systematic design approach for compact polarization-independent mode-size transformers based on tapered resonant vertical couplers with transfer efficiencies greater than 90%. Resonant coupling occurs at a critical taper width having equal TE and TM effective index. Being polarization-independent broadens the usefulness of vertical coupler as a building block for minimizing insertion loss in photonic integrated circuits.