Ending Neonatal Deaths From Hypothermia in Sub-Saharan Africa: Call for Essential Technologies Tailored to the Context.

Neonatal death represents a major burden in Sub-Saharan Africa (SSA), where the main conditions triggering mortality, such as prematurity, labor complications, infections, and respiratory distress syndrome, are frequently worsened by hypothermia, which dramatically scales up the risk of death. In SSA, the lack of awareness on the procedures to prevent hypothermia and the shortage of essential infant devices to treat it are hampering the reduction of neonatal deaths associated to hypothermia. Here, we offer a snapshot on the current available medical solutions to prevent and treat hypothermia in SSA, with a focus on Kenya. We aim to provide a picture that underlines the essential need for infant incubators in SSA. Specifically, given the inappropriateness of the incubators currently on the market, we point out the need for reinterpretation of research in the field, calling for technology-based solutions tailored to the SSA context, the need, and the end-user.

High power and single mode quantum cascade lasers.

We present a single mode quantum cascade laser with nearly 1 W optical power. A buried distributed feedback reflector is used on the back section for wavelength selection. The laser is 6 mm long, 3.5 µm wide, mounted episide-up and the laser facets are left uncoated. Laser emission is centered at 4.68 µm. Single-mode operation with a side mode suppression ratio of more than 30 dB is obtained in whole range of operation. Farfield measurements prove a symmetric, single transverse-mode emission in TM00-mode with typical divergences of 41° and 33° in the vertical and horizontal direction respectively. This work shows the potential for simple fabrication of high power lasers compatible with standard DFB processing.

Terahertz quantum cascade lasers.

Recent developments in terahertz quantum cascade lasers are reviewed. Structures operating from a wavelength of lambda = 66 microm down to lambda = 87 microm are demonstrated. These devices used either a three-quantum-well chirped-superlattice active region or an active region based on a bound-to-continuum transition. The comparison between structures grown in a waveguide based on a single interface plasmon and a buried contact and (non-lasing) structures using a double plasmon waveguide demonstrates the importance of waveguide design on the operation of such devices. Continuous-wave operation up to a maximum temperature of 55 K with up to 15 mW output power at 10 K was demonstrated.