Photonic topological systems may be exploited in topological quantum light generation, the development of topological lasers, the implementation of photonic routing systems and optical parametric amplification. Here, we leverage the strong light confinement of an ultra-silicon-rich nitride (USRN) topological waveguide adopting the 1D Su-Schrieffer-Heeger (SSH) system with a topological domain wall. We present the formation and propagation of temporal optical solitons in the topological waveguide, exhibiting two-fold temporal compression.
View Article and Find Full Text PDFInt J Surg
August 2024
Background: Ageing population is a worldwide phenomenon with correspondingly higher proportion of older patients being treated in the hospital setting. Sarcopenia, which increases with age, has serious negative implications on health, hospitalisation, and overall postoperative recovery. There is no mutual consensus on perioperative management of sarcopenia in surgical patients in Singapore.
View Article and Find Full Text PDFBackground: Branched chain amino acid (BCAA) supplementation has been associated with favourable outcomes in liver malignancies requiring definitive resection or liver transplantation. Currently, there are no updated systematic reviews evaluating the efficacy of perioperative BCAA supplementation in patients undergoing surgery for liver cancer.
Aim: To evaluate the efficacy of perioperative BCAA supplementation in patients undergoing surgery for liver cancer.
The nutritional status of hospitalised patients is often at risk or compromised and predisposed to further deterioration after discharge, leading to poor clinical outcomes, high healthcare costs, and poor quality of life. This paper aims to provide evidence-based best-practice recommendations to address this, supported by a national survey of healthcare professionals in Singapore and reviewed by a multidisciplinary expert panel under the Sarcopenia Interest Group of Society of Parenteral and Enteral Nutrition Singapore (SingSPEN). We advocate screening all patients with a validated tool which includes a disease activity/burden component, an easily accessible dietitian referral pathway for patients at risk of malnutrition, and an individualised nutrition care plan formulated and delivered using a multidisciplinary team approach for patients at risk or with malnutrition.
View Article and Find Full Text PDFNonlinear propagation in periodic media has been studied for decades, yielding demonstrations of numerous phenomena including strong temporal compression and slow light generation. Gap solitons, that propagate at frequencies inside the stopband, have been observed in optical fibres but have been elusive in photonic chips. In this manuscript, we investigate nonlinear pulse propagation in a chip-based nonlinear Bragg grating at frequencies inside the stopband and observe clear, unequivocal signatures of gap soliton propagation, including slow light, intensity-dependent transmission, intensity-dependent temporal delay and gap soliton compression.
View Article and Find Full Text PDFTopological boundary states are well localized eigenstates at the boundary between two different bulk topologies. As long as bulk topology is preserved, the topological boundary mode will endure. Here, we report topological nonlinear parametric amplification of light in a dimerized coupled waveguide system based on the Su-Schrieffer-Heeger model with a domain wall.
View Article and Find Full Text PDFChemical vapor deposition-based growth techniques allow flexible design of complementary metal-oxide semiconductor (CMOS) compatible materials. Here, we report the deuterated silicon-rich nitride films grown using plasma-enhanced chemical vapor deposition. The linear and nonlinear properties of the films are characterized, and we experimentally confirm that the silicon-rich nitride films grown with SiD eliminates Si-H and N-H related absorption.
View Article and Find Full Text PDFSupercontinuum generation is demonstrated in a 3-mm-long ultra-silicon-rich nitride (USRN) waveguide by launching 500 fs pulses centered at 1555 nm with a pulse energy of 17 pJ. The generated supercontinuum is experimentally characterized to possess a high spectral coherence, with an average |g| exceeding 0.90 across the wavelength range of the coherence measurement (1260 nm to 1700 nm).
View Article and Find Full Text PDFBMC Womens Health
April 2022
Objectives: To evaluate the effect of intraperitoneal normal saline instillation (INSI) of 15 mL/kg body weight on postoperative pain after a gynaecological laparoscopic procedure.
Design: Randomised controlled trial.
Setting: University Hospital in Kuala Lumpur, Malaysia.
Ultra-silicon-rich nitride with refractive indices ~ 3 possesses high nonlinear refractive index-100× higher than stoichiometric silicon nitride and presents absence of two-photon absorption, making it attractive to be used in nonlinear integrated optics at telecommunications wavelengths. Despite its excellent nonlinear properties, ultra-silicon-rich nitride photonics devices reported so far still have fairly low quality factors of [Formula: see text], which could be mainly attributed by the material absorption bonds. Here, we report low temperature plasma-deposited dichlorosilane-based ultra-silicon-rich nitride (SiN) with lower material absorption bonds, and ~ 2.
View Article and Find Full Text PDFThe generation of optical pulse trains from continuous-wave light has attracted growing attention in recent years because it provides a simple way to obtain high repetition rate ultrashort pulses. While pulse generation has been extensively demonstrated in optical fibers, pulse train generation from weak, continuous wave light in photonic chips has posed significant challenges because of the short interaction length and therefore difficulty in acquiring sufficient new frequency content, and/or absence of the appropriate dispersion environment. In this manuscript, we report the pulse train generation of a low continuous-wave signal to 18 ps, by leveraging cross-phase modulation induced by co-propagating pump pulses with a peak power of 3.
View Article and Find Full Text PDFOptical pulses are fundamentally defined by their temporal and spectral properties. The ability to control pulse properties allows practitioners to efficiently leverage them for advanced metrology, high speed optical communications and attosecond science. Here, we report 11× temporal compression of 5.
View Article and Find Full Text PDFPreterm birth is a global concern with considerable morbidity and mortality. Intrapartum infection is a known cause of preterm birth and infection is one of the infections contributing to preterm birth. We report a case of preterm birth of a trisomy-21 neonate to a mother with positive from an intra-operative placental swab sample and discussed the relationship of this bacteria and preterm delivery, and the role of postpartum antibiotics use in this case.
View Article and Find Full Text PDFInfrared gas sensors have been proven promising for broad applications in Internet of Things and Industrial Internet of Things. However, the lack of miniaturized light sources with good compatibility and tunable spectral features hinders their widespread utilization. Herein, a strategy is proposed to increase the radiated power from microelectromechanical-based thermal emitters by coating with graphene oxide (GO).
View Article and Find Full Text PDFAn 8-channel coarse wavelength division multiplexer (CWDM) based on coupled vertical gratings has been designed, fabricated and characterized. The devices are implemented on the ultra-silicon-rich nitride (USRN) platform. The demonstrated device possesses 8 CWDM channels.
View Article and Find Full Text PDFThe dispersive nonlinear refractive index of ultra-silicon-rich nitride, and its two-photon and three-photon absorption coefficients are measured in the wavelength range between 0.8 µm-1.6 µm, covering the O- to L - telecommunications bands.
View Article and Find Full Text PDFAsia Pac J Clin Nutr
September 2019
Background And Objectives: Malnutrition is under-recognized and under-treated in Asia due to resource constraints, lack of awareness and knowledge among healthcare professionals and patients, and lack of standardized procedures for malnutrition management. While international guidelines for the management of malnutrition are available, they may not be easily applicable to the patient population and healthcare settings within Southeast Asia. This paper provides consensus recommendations, developed by the Regional Nutrition Working Group, to foster evidence-based nutritional care in Southeast Asia to improve patient outcomes.
View Article and Find Full Text PDFElectrically 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.
View Article and Find Full Text PDFA graded-index multilayer thin-film stack is optimized to act as a cladding layer on top of a silicon (Si) nanowaveguide and also a collimator for chip coupling where the waveguide ends. The numerical example shows an optimized graded-index profile from 2.35 to 1.
View Article and Find Full Text PDFWe 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.
View Article and Find Full Text PDFSilicon-rich nitride films are developed and explored using an inductively coupled plasma chemical vapor deposition system at low temperature of 250 °C with an ammonia-free gas chemistry. The refractive index of the developed silicon-rich nitride films can increase from 2.2 to 3.
View Article and Find Full Text PDFA 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.
View Article and Find Full Text PDF