Rats to the Rescue: Results of the First Tests on a Real Minefield

The study in this article showed that using rats to evaluate mine risk is a very promising mine-detection method. When three rats were used to evaluate a contaminated area, the success rate was 95 percent, showing that rats can be a speedy and cost-effective means of mine detection

Supercontinuum generation assisted by dispersive waves trapping in dispersion-managed integrated silicon waveguides

Compact chip-scale comb sources are of significant interest for many practical applications. Here, we experimentally study the generation of supercontinuum (SC) in an axially varying integrated waveguide. We show that the local tuning of the dispersion enables the continuous blue shift of dispersive waves thanks to their trapping by the strongly compressed pump pulse. This mechanism provides new insight into supercontinuum generation in a dispersion varying integrated waveguide. Pumped close to 2.2 $\mu$m in the femtosecond regime and at a pulse energy of $\sim$ 4 pJ, the output spectrum extends from 1.1 $\mu$m up to 2.76 $\mu$m and shows good coherence properties. Octave-spanning SC is also observed at input energy as low as $\sim$ 0.9 pJ. We show that the supercontinuum is more robust against variations of the input pulse parameters and is also spectrally flatter in our numerically optimized waveguide than in fixed-width waveguides. This research demonstrates the potential of dispersion varying waveguides for coherent SC generation and paves the way for integrated low power applications, such as chip-scale frequency comb generation, precision spectroscopy, optical frequency metrology, and wide-band wavelength division multiplexing in the near-infrared

Micro-transfer printing of lithium niobate on silicon nitride

Successful micro-transfer printing of lithium niobate on a silicon nitride platform is demonstrated. A proof of concept electro-optical modulator is fabricated using this hybrid integration method which shows a half-wave voltage-length product VπLπ=5.5 Vcm and insertion losses of 7 dB

Second Harmonic Generation Enabled by Longitudinal Electric Field Components in Photonic Wire Waveguides

We investigate type I second harmonic generation in III-V semiconductor wire waveguides aligned with a crystallographic axis. In this direction, because of the single nonzero tensor element of III-V semiconductors, only frequency conversion by mixing with the longitudinal components of the optical fields is allowed. We experimentally study the impact of the propagation direction on the conversion efficiency and confirm the role played by the longitudinal components through the excitation of an antisymmetric second harmonic higher order mode

Appropriate referral and selection of patients with chronic pain for spinal cord stimulation: European consensus recommendations and e-health tool

Background: Spinal cord stimulation (SCS) is an established treatment for chronic neuropathic, neuropathic-like and ischaemic pain. However, the heterogeneity of patients in daily clinical practice makes it often challenging to determine which patients are eligible for this treatment, resulting in undesirable practice variations. This study aimed to establish patient-specific recommendations for referral and selection of SCS in chronic pain. Methods: A multidisciplinary European panel used the RAND/UCLA Appropriateness Method (RUAM) to assess the appropriateness of (referral for) SCS for 386 clinical scenarios in four pain areas: chronic low back pain and/or leg pain, complex regional pain syndrome, neuropathic pain syndromes and ischaemic pain syndromes. In addition, the panel identified a set of psychosocial factors that are relevant to the decision for SCS treatment. Results: Appropriateness of SCS was strongly determined by the neuropathic or neuropathic-like pain component, location and spread of pain, anatomic abnormalities and previous response to therapies targeting pain processing (e.g. nerve block). Psychosocial factors considered relevant for SCS selection were as follows: lack of engagement, dysfunctional coping, unrealistic expectations, inadequate daily activity level, problematic social support, secondary gain, psychological distress and unwillingness to reduce high-dose opioids. An educational e-health tool was developed that combines clinical and psychosocial factors into an advice on referral/selection for SCS. Conclusions: The RUAM was useful to establish a consensus on patient-specific criteria for referral/selection for SCS in chronic pain. The e-health tool may help physicians learn to apply an integrated approach of clinical and psychosocial factors. Significance: Determining the eligibility of SCS in patients with chronic pain requires careful consideration of a variety of clinical and psychosocial factors. Using a systematic approach to combine evidence from clinical studies and expert opinion, a multidisciplinary European expert panel developed detailed recommendations to support appropriate referral and selection for SCS in chronic pain. These recommendations are available as an educational e-health tool (https://www.scstool.org/)

Octave-spanning coherent supercontinuum generation in an AlGaAs-on-insulator waveguide

We demonstrate supercontinuum generation over an octave spaning from 1055 to 2155 nm on the highly nonlinear aluminum gallium arsenide (AlGaAs)-on-insulator platform. This is enabled by the generation of two dispersive waves in a 3-mm-long dispersion-engineered nano-waveguide. The waveguide is pumped at telecom wavelengths (1555 nm) with 3.6 pJ femtosecond pulses. We experimentally validate the coherence of the generated supercontinuum around the pump wavelength (1450-1750 nm), and our numerical simulation shows a high degree of coherence over the full spectrum. (C) 2020 Optical Society of Americ

Micro-transfer-printed III-V-on-Si semiconductor optical amplifier with 15 dBm output saturation power

We demonstrate a high-saturation power III-V-onSi semiconductor optical amplifier (SOA) with a tapered design realized using micro-transfer-printing integration technology. The SOA provides a 9 dB small-signal gain and an output saturation power of 15 dBm at the wavelength of 1573 nm

Octave spanning supercontinuum generation in dispersion-managed silicon waveguides

Coherent supercontinuum spanning [1.2-2.7] μm is experimentally demonstrated in dispersion-managed silicon waveguides. We show that part of the spectrum is broadened by the trapping of dispersive waves, lowering the power to get octave-spanning spectra