Thick waveguides of low-stress stoichiometric silicon nitride on sapphire (SiNOS).

Low-stress stoichiometric silicon nitride (SiN) waveguides with an unprecedented thickness of up to 1350 nm and a width in the range of 2.2 - 2.7 µm are fabricated using a single LPCVD step on sapphire substrates (SiNOS).

Femtosecond pulse amplification on a chip.

Femtosecond laser pulses enable the synthesis of light across the electromagnetic spectrum and provide access to ultrafast phenomena in physics, biology, and chemistry. Chip-integration of femtosecond technology could revolutionize applications such as point-of-care diagnostics, bio-medical imaging, portable chemical sensing, or autonomous navigation. However, current chip-integrated pulse sources lack the required peak power, and on-chip amplification of femtosecond pulses has been an unresolved challenge.

High on-chip gain spiral AlO:Er waveguide amplifiers.

We demonstrate reactively sputtered AlO:Er waveguide amplifiers with an erbium concentration of 3.9 × 10 ions/cm, capable of achieving over 30 dB small signal net gain at 1532 nm using bidirectional pumping at 1480 nm. We observe on chip output powers of 10.

Safety and efficacy of the two doses conjugated protein-based SOBERANA-02 COVID-19 vaccine and of a heterologous three-dose combination with SOBERANA-Plus: a double-blind, randomised, placebo-controlled phase 3 clinical trial.

Background: SOBERANA-02 is a COVID-19 conjugate vaccine (recombinant RBD conjugated to tetanus toxoid). Phases 1/2 clinical trials demonstrated high immunogenicity, promoting neutralising IgG and specific T-cell response. A third heterologous dose of SOBERANA-Plus (RBD-dimer) further increased neutralising antibodies.

Modular microring laser cavity sensor.

We propose and experimentally demonstrate a modular microring laser (MML) cavity for sensing applications. The proposed MML permits much more design freedom compared with a traditional simple ring cavity by decoupling the performance parameters into several regions in the cavity. Thus, the different biosensor performance parameters can be optimized semi-independently limiting the need for trade-offs on the design of the biosensing device.

Mode-splitting in a microring resonator for self-referenced biosensing.

Self-referenced biosensing based on mode-splitting on a microring resonator is experimentally demonstrated. A Bragg grating integrated on the surface of the ring provides coupling between the clockwise and counterclockwise travelling modes of the pristine ring resonator lifting their degeneracy. The amount of mode-splitting is directly related to the reflectivity of the grating and it is only affected by structurally modifying the grating.

Redeposition-Free Deep Etching in Small KY(WO) Samples.

KY(WO) is a promising material for on-chip laser sources. Deep etching of small KY(WO) samples in combination with various thin film deposition techniques is desirable for the manufacturing of such devices. There are, however, several difficulties that need to be overcome before deep etching of KY(WO) can be realized in small samples in a reproducible manner.

AlO:Yb integrated microdisk laser label-free biosensor.

Whispering gallery mode resonator lasers hold the promise of an ultralow intrinsic limit of detection. However, the widespread use of these devices for biosensing applications has been hindered by the complexity and lack of robustness of the proposed configurations. In this work, we demonstrate biosensing with an integrated microdisk laser.

Development of low-loss TiO waveguides.

TiO channel waveguides were fabricated using a DC sputter deposition process, followed by photolithography and reactive ion etching. A SiO cladding was deposited using evaporation. SEM, TEM and Raman measurements indicate the presence of both an amorphous and a crystalline phase.

Comparative study of multiple thiol-based self-assembled monolayer coatings for the SERS detection of nitrite, nitrate, and perchlorate anions in water.

Raman-based sensors represent a promising solution to enable both detection and fingerprinting of anionic pollutants in the water distribution network. Due to the weak nature of Raman scattering, a signal intensity enhancement mechanism, such as surface enhanced Raman spectroscopy (SERS), is required. Given the combination of SERS being a first layer effect and the low affinity for metallic surfaces shown by anions, functionalization of the SERS substrates using positively charged self-assembled monolayers (SAMs) is required to guarantee a strong SERS signal.

Lapping and Polishing of Crystalline KY(WO): Toward High Refractive Index Contrast Slab Waveguides.

Rare-earth ion-doped potassium yttrium double tungstate, RE:KY(WO), is a promising candidate for small, power-efficient, on-chip lasers and amplifiers. Thin KY(WO)onglass layers with thicknesses ranging between 0.9 and 1.

High index contrast photonic platforms for on-chip Raman spectroscopy.

Nanophotonic waveguide enhanced Raman spectroscopy (NWERS) is a sensing technique that uses a highly confined waveguide mode to excite and collect the Raman scattered signal from molecules in close vicinity of the waveguide. The most important parameters defining the figure of merit of an NWERS sensor include its ability to collect the Raman signal from an analyte, i.e.

AlO microring resonators for the detection of a cancer biomarker in undiluted urine.

Concentrations down to 3 nM of the rhS100A4 protein, associated with human tumor development, have been detected in undiluted urine using an integrated sensor based on microring resonators in the emerging AlO photonic platform. The fabricated microrings were designed for operation in the C-band (λ = 1565 nm) and exhibited a high-quality factor in air of 3.2 × 10.

High optical gain in erbium-doped potassium double tungstate channel waveguide amplifiers.

We report on the optical-gain properties of channel waveguides patterned into lattice-matched KGdxLuyErxy(WO) layers grown onto undoped KY(WO) substrates by liquid phase epitaxy. A systematic investigation of gain is performed for five different Er concentrations in the range of 0.75 to 10at.

Low-loss, broadband and high fabrication tolerant vertically tapered optical couplers for monolithic integration of SiN and polymer waveguides.

A low-loss, broadband and high fabrication tolerant optical coupler for the monolithic integration of SiN and polymer waveguides is designed and experimentally demonstrated. The coupler is based on the adiabatic vertical tapering of the SiN waveguides. Low-loss operation is experimentally verified at both 976 and 1460-1635 nm wavelengths.

Vulnerability to Psychopathology and Dimensions of Personality in Patients With Fibromyalgia.

Objective: Fibromyalgia (FM) patients may present psychopathology and some characteristic personality traits that may affect their adaptation to the disease. The aim of this paper was to study the relationship between personality dimensions according to the psychobiological model of Cloninger and the presence of psychopathology.

Materials And Methods: The study sample consisted of 42 patients with FM and 38 pain-free controls.

Temperature-dependent absorption and emission of potassium double tungstates with high ytterbium content.

We study the spectroscopic properties of thin films of potassium ytterbium gadolinium double tungstates, KYbGd(WO), and potassium ytterbium lutetium double tungstates, KYbLu(WO), specifically at the central absorption line near 981 nm wavelength, which is important for amplifiers and lasers. The absorption cross-section of both thin films is found to be similar to those of bulk potassium rare-earth double tungstates, suggesting that the crystalline layers retain their spectroscopic properties albeit having >50 at.% Yb concentration.

Prevalence of human T-cell lymphotropic virus I and II in Colombian blood donors, 2001-2014: Implications for transfusion safety.

Introduction: The human T-cell lymphotropic virus (HTLV) 1 and 2 cause various clinical disorders associated with degenerative diseases. Blood transfusion is a primary mechanism of transmission that is associated with the use of cellular components such as red blood cells. 

Objective: To describe the epidemiology of HTLV 1 and 2 in blood donors in Colombia from 2001-2014.

Cloninger's psychobiological model of personality and psychological distress in fibromyalgia.

Aim: Personality can play an important role in the clinical symptoms of fibromyalgia (FM). The aim of this study is to identify personality profiles in FM patients and the possible presence of personality disorder (PD) from the Temperament and Character Inventory-Revised (TCI-R), and to assess whether personality dimensions are related to psychological distress in FM.

Method: The sample consisted of 42 patients with FM and 38 healthy controls.

Erbium-doped spiral amplifiers with 20 dB of net gain on silicon.

Spiral-waveguide amplifiers in erbium-doped aluminum oxide on a silicon wafer are fabricated and characterized. Spirals of several lengths and four different erbium concentrations are studied experimentally and theoretically. A maximum internal net gain of 20 dB in the small-signal-gain regime is measured at the peak emission wavelength of 1532 nm for two sample configurations with waveguide lengths of 12.

Altered functional magnetic resonance imaging responses to nonpainful sensory stimulation in fibromyalgia patients.

Objective: Fibromyalgia (FM) is a disorder characterized by chronic pain and enhanced responses to acute noxious events. However, the sensory systems affected in FM may extend beyond pain itself, as FM patients show reduced tolerance to non-nociceptive sensory stimulation. Characterizing the neural substrates of multisensory hypersensitivity in FM may thus provide important clues about the underlying pathophysiology of the disorder.

Thulium channel waveguide laser with 1.6 W of output power and ∼80% slope efficiency.

Laser experiments were performed on buried, ridge-type channel waveguides in 8 at.% thulium-doped, yttrium-gadolinium-lutetium co-doped potassium double tungstate. By pumping with a Ti:sapphire laser at 794 nm, 1.

The contribution of sensory system functional connectivity reduction to clinical pain in fibromyalgia.

Fibromyalgia typically presents with spontaneous body pain with no apparent cause and is considered pathophysiologically to be a functional disorder of somatosensory processing. We have investigated potential associations between the degree of self-reported clinical pain and resting-state brain functional connectivity at different levels of putative somatosensory integration. Resting-state functional magnetic resonance imaging was obtained in 40 women with fibromyalgia and 36 control subjects.

Low-loss sharp bends in polymer waveguides enabled by the introduction of a thin metal layer.

Embodying a thin metallic layer underneath the core of a sharply bent polymer waveguide is shown in this work to considerably reduce the total losses of both the quasi-transverse-electric and quasi-transverse-magnetic modes. The computational results show a total loss as low as ~0.02 dB/90° for the quasi-transverse-electric mode for radii between 6 and 13 µm at the wavelength of 1.