Compact and low power consumption tunable photonic crystal nanobeam cavity

A proof-of-concept for a new and entirely CMOS compatible tunable nanobeam cavity is demonstrated in this paper. Preliminary results show that a compact nanobeam cavity (~20 μm^2) with high Q-factor (~50,000) and integrated with a micro-heater atop, is able of tuning the resonant wavelength up to 15 nm with low power consumption (0.35nm/mW), and of attaining high modulation depth with only ~100 μW. Additionally, a tunable bi-stable behavior is reported

Metawaveguide for Asymmetric Interferometric Light-Light Switching

Light-light switching typically requires strong nonlinearity where intense laser fields route and direct data flows of weak power, leading to a high power consumption that limits its practical use. Here we report an experimental demonstration of a metawaveguide that operates exactly in the opposite way in a linear regime, where an intense laser field is interferometrically manipulated on demand by a weak control beam with a modulation extinction ratio up to approximately 60 dB. This asymmetric control results from operating near an exceptional point of the scattering matrix, which gives rise to intrinsic asymmetric reflections of the metawaveguide through delicate interplay between index and absorption. The designed metawaveguide promises low-power interferometric light-light switching for the next generation of optical devices and networks

Adaptation of the generic DISABKIDS® module for Brazilian children and adolescents with chronic disorders

OBJECTIVES: to describe the process of cultural adaptation to Brazil Generic Module DISABKIDS for Chronic Conditions (DCGM-37), a generic instrument for measuring the quality of life of children and adolescents with chronic conditions. METHODS: a cross-cutting methodological study was carried out in pediatric outpatients clinics in Brazil, covering 118 children/adolescents with asthma or diabetes and their parents or carers. Translation, back-translation and cultural adaptation were carried out to obtain conceptual and semantic equivalence at the level of individual items.Equivalence was measured statistically by describing the initial psychometric properties, using validity and reliability criteria. RESULTS: most of the items were considered relevant and 14 of them were modified following the semantic validation phase. Values for Cronbach's alpha were α=0.92 and α=0.93, for the version for children and adolescents and the version for parents and carers, respectively. Analysis of correlations between items and dimensions revealed a satisfactory degree of convergent and discriminant validity. CONCLUSIONS: the initial phase indicates that DISABKIDS module is a valid and reliable tool for measuring quality of life in a Brazilian context.OBJETIVOS: descrever o processo de adaptação cultural para o Brasil do Módulo Genérico DISABKIDS para Condicões Crônicas (DCGM-37), um instrumento genérico para mensuração da qualidade de vida de crianças e adolescentes com condições crônicas. MÉTODOS: estudo metodológico, transversal, conduzido em ambulatórios pediátricos brasileiros, incluindo 118 crianças/adolescentes com asma ou diabetes e seus pais/cuidadores. Os processos de tradução-retrotradução e adaptação cultural foram realizados visando a obter equivalência conceitual e semântica em nível de itens. A equivalência de medida foi avaliada por análise estatística, realizada para descrição das propriedades psicométricas iniciais, segundo os critérios de validade e confiabilidade. RESULTADOS: a maioria dos itens foi considerada relevante e 14 deles foram modificados após a fase de validação semântica. Valores para a estatística alfa de Cronbach foram α=0,92 e α=0,93, para a versão crianças/adolescentes e pais/cuidadores respectivamente. A análise das correlações entre itens e dimensões mostrou validade convergente e discriminante satisfatórias. CONCLUSÕES: a fase inicial indica que o instrumento deverá constituir ferramenta válida e confiável para mensuração da qualidade de vida na realidade brasileira.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP)Universidade Federal do Rio Grande do Sul Departamento de Odontologia Preventiva e SocialUniversidade de São Paulo Escola de Enfermagem de Ribeirão PretoUniversitätsklinikum Hamburg-Eppendorf Instituto e Policlínica de Medicina PsicológicaUNIFESPSciEL

Experimental realization of Bloch oscillations in a parity-time synthetic silicon photonic lattice

As an important electron transportation phenomenon, Bloch oscillations have been extensively studied in condensed matter. Due to the similarity in wave properties between electrons and other quantum particles, Bloch oscillations have been observed in atom lattices, photonic lattices, and so on. One of the many distinct advantages for choosing these systems over the regular electronic systems is the versatility in engineering artificial potentials. Here by utilizing dissipative elements in a CMOS-compatible photonic platform to create a periodic complex potential and by exploiting the emerging concept of parity-time synthetic photonics, we experimentally realize spatial Bloch oscillations in a non-Hermitian photonic system on a chip level. Our demonstration may have significant impact in the field of quantum simulation by following the recent trend of moving complicated table-top quantum optics experiments onto the fully integrated CMOS-compatible silicon platform

Experimental demonstration of a unidirectional reflectionless parity-time metamaterial at optical frequencies

Invisibility by metamaterials is of great interest, where optical properties are manipulated in the real permittivity– permeability plane. However, the most effective approach to achieving invisibility in various military applications is to absorb the electromagnetic waves emitted from radar to minimize the corresponding reflection and scattering, such that no signal gets bounced back. Here, we show the experimental realization of chip-scale unidirectional reflectionless optical metamaterials near the spontaneous parity-time symmetry phase transition point where reflection from one side is significantly suppressed. This is enabled by engineering the corresponding optical properties of the designed paritytime metamaterial in the complex dielectric permittivity plane. Numerical simulations and experimental verification consistently exhibit asymmetric reflection with high contrast ratios around a wavelength of of 1,550 nm. The demonstrated unidirectional phenomenon at the corresponding parity-time exceptional point on-a-chip confirms the feasibility of creating complicated on-chip parity-time metamaterials and optical devices based on their properties

Hybrid single quantum well InP/Si nanobeam lasers for silicon photonics

We report on a hybrid InP/Si photonic crystal nanobeam laser emitting at 1578 nm with a low threshold power of ∼14.7 μW. Laser gain is provided from a single InAsP quantum well embedded in a 155 nm InP layer bonded on a standard silicon-on-insulator wafer. This miniaturized nanolaser, with an extremely small modal volume of 0.375(λ/n)^3, is a promising and efficient light source for silicon photonics

Adaptación cultural y propiedades psicométricas iniciales del instrumento DISABKIDS ® – Cystic Fibrosis Module – versión brasileña

This study aimed to perform the cultural adaptation and describe the initial psychometric properties of the DISABKIDS®−Cystic Fibrosis Module instrument to measure health-related quality of life for children and adolescents and their parents/caregivers. Methodological study of sequential development, including 126 participants in four Brazilian states. Involved translation and back translation of items, semantic and conceptual equivalence, face validity and description of the initial psychometric properties related to the construct and reliability. For semantic equivalence of the adapted version, there were adjustments in the phrasing of an item. The instrument showed satisfactory internal consistency with Cronbach’s alpha values between 0.70 and 0.85, convergent validity with correlation values above 0.40 in 85% of the items and divergent validity with scale fit higher than 75%. The Brazilian version of DISABKIDS® – CFM will certainly constitute a valid and reliable instrument for measuring the quality of life of Brazilian children and adolescents with cystic fibrosis.Este estudio tuvo como objetivo adaptar culturalmente y describir las propiedades psicométricas iniciales del instrumento de medida de la calidad de vida relacionada a la salud, DISABKIDS® – Cystic Fibrosis Module para niños/adolescentes y sus padres/cuidadores. Estudio metodológico de desarrollo secuencial, incluyendo 126 participantes en cuatro estados brasileños. Envolvió la traducción y retro-traducción de los ítems, la equivalencia conceptual y semántica, la validez externa y la descripción de las propiedades psicométricas iniciales con relación al constructo y la confiabilidad. Para la equivalencia semántica de la versión adaptada hubo ajustes en la redacción de un ítem. El instrumento presentó consistencia interna satisfactoria con valores de alfa de Cronbach entre 0,70 y 0,85, validez convergente con valores de correlación superiores a 0,40 en 85% de los ítems y validez divergente con valores de ajuste superiores a 75%. La versión brasileña del DISABKIDS® - CFM ciertamente será un instrumento válido y confiable para medir la Calidad de Vida de niños y adolescentes con fibrosis quística.Este estudo objetivou adaptar culturalmente e descrever as propriedades psicométricas iniciais do instrumento de mensuração de qualidade de vida relacionada à saúde DISABKIDS® − Cystic Fibrosis Module para crianças e adolescentes e seus pais/cuidadores. Estudo metodológico de desenvolvimento sequencial, incluindo 126 participantes em quatro estados brasileiros. Envolveu tradução e retrotradução dos itens, equivalência conceitual e semântica, validade de face e descrição das propriedades psicométricas iniciais relacionadas ao construto e fidedignidade . Para equivalência semântica da versão adaptada houve ajustes na redação de um item. O instrumento apresentou consistência interna satisfatória com valores de alfa de Cronbach entre 0,70 e 0,85, validade convergente com valores de correlação acima 0,40 em 85% dos itens e validade divergente com valores de ajuste superiores a 75%. A versão brasileira do DISABKIDS® - CFM certamente se constituirá em um instrumento válido e confiável para a mensuração da qualidade de vida de crianças e adolescentes brasileiros com fibrose cística.Universidade de São Paulo Escola de Enfermagem de Ribeirao PretoUniversidade Federal de São Paulo (UNIFESP)Universidade Federal do Rio Grande do Sul Departamento de Odontologia Preventiva e SocialHospital das Clinicas Hospital das ClinicasFaculdade de Medicina Faculdade de MedicinaUniversidade de São PauloUniversitatsklinikim Hambug-EppendorfUNIFESPSciEL

Reconfigurable silicon thermo-optical ring resonator switch based on Vernier effect control

A proof-of-concept for a new and entirely CMOS compatible thermo-optic reconfigurable switch based on a coupled ring resonator structure is experimentally demonstrated in this paper. Preliminary results show that a single optical device is capable of combining several functionalities, such as tunable filtering, non-blocking switching and reconfigurability, in a single device with compact footprint (~50μm x 30μm)

Experimental demonstration of a reconfigurable silicon thermo-optical device based on spectral tuning of ring resonators for optical signal processing

We have experimentally demonstrated a reconfigurable silicon thermo-optical device able to tailor its intrinsic spectral optical response by means of the thermo-optical control of individual and uncoupled resonant modes of micro-ring resonators. Preliminarily results show that the device’s optical response can be tailored to build up distinct and reconfigurable logic levels for optical signal processing, as well as control of overall figures of merit, such as free-spectral-range, extinction ratio and 3dB bandwidth. In addition, the micro-heaters on top of the ring resonators are able to tune the resonant wavelength with efficiency of 0.25 nm/mW within a range of up to 10 nm, as well as able to switch the resonant wavelength within fall and rise time of 15 μs