1. Type 1 diabetes (due to b-cell destruction, usually leading to absolute insulin deficiency) 2. Type 2 diabetes (due to a progressive insulin secretory defect on the background of insulin resistance) 3. Gestational diabetes mellitus (GDM) (diabetes diagnosed in the second or third trimester of pregnancy that is not clearly overt diabetes) 4. Specific types of diabetes due to other causes, e.g., monogenic diabetes syndromes (such as neonatal diabetes and maturity-onset diabetes of the young [MODY]), diseases of the exocrine pancreas (such as cystic fibrosis), and drugor chemical-induced diabetes (such as in the treatment of HIV/AIDS or after organ transplantation)

Classification and diagnosis of diabetes

We investigate the design, fabrication, and experimental characterization of high quality factor photonic crystal nanobeam cavities in silicon. Using a five-hole tapered one-dimensional photonic crystal mirror and precise control of the cavity length, we designed cavities with theoretical quality factors as high as 1.4×107. By detecting the cross-polarized resonantly scattered light from a normally incident laser beam, we measure a quality factor of nearly 7.5×105. The effect of cavity size on mode frequency and quality factor was simulated and then verified experimentally.

High quality factor photonic crystal nanobeam cavities

We demonstrate room-temperature pulsed laser emission from optically pumped metallo-dielectric cavities that are smaller than their emission wavelength in all three dimensions. The cavity consists of an aluminium/silica bi-layer shield surrounding an InGaAsP disk in which the thickness of the silica layer is optimized to minimize the gain threshold of the laser. The lasers are pumped using a 1,064-nm pulsed fibre laser with a pulse width of 12 ns and repetition rate of 300 kHz. Lasing emission at 1.43 µm is observed from a laser with slightly elliptical gain core with major and minor diameters of 490 and 420 nm, respectively. Owing to the isolation provided by the aluminium shield, this laser design approach can be used to create arrays of uncoupled lasers with emitter densities that are close to the Rayleigh resolution limit. Room-temperature lasing from metallo-dielectric cavities that are smaller than their emission wavelength in all three dimensions is reported. The cavity consists of an aluminium/silica bi-layer shield that surrounds an InGaAsP disk. The gain threshold of the laser is minimized by optimizing the thickness of the silica layer.

Room-temperature subwavelength metallo-dielectric lasers

Coupled optical resonators are one approach to slowing the propagation of light. An array of more than 100 such resonators has now been demonstrated using a photonic crystal. Such a structure can slow light down to below 1% of its speed in a vacuum.

Large-scale arrays of ultrahigh-Q coupled nanocavities

Photonic crystal nanobeam cavities are versatile platforms of interest for optical communications, optomechanics, optofluidics, cavity QED, etc. In a previous work [Appl. Phys. Lett. 96, 203102 (2010)], we proposed a deterministic method to achieve ultrahigh Q cavities. This follow-up work provides systematic analysis and verifications of the deterministic design recipe and further extends the discussion to air-mode cavities. We demonstrate designs of dielectric-mode and air-mode cavities with Q > 10⁹, as well as dielectric-mode nanobeam cavities with both ultrahigh-Q (> 10⁷) and ultrahigh on-resonance transmissions (T > 95%).

Deterministic design of wavelength scale, ultra-high Q photonic crystal nanobeam cavities

In this study, the low-group velocity slow-light mach-zehnder interferometer (MZI) modulator, low loss and high efficiency for two modulator substrate lithium niobate (LN) and silicon were presented and optimized at 155µm operating wavelength The high power consumption of conventional modulator was the major drawback in the operation of modulators Therefore, it was a good time for low-power modulator design and development and to compare the LN and Silicon modulator on the phase shifted using the slow-light technique by designing the full MZI modulator consisting of splitter and combiner on both substrates The phase shift of LN is 2% compared with the silicon 009% and higher phase shift give better performance with low power consumption due to the change of modulating voltage of the MZI modulator for LN while the silicon depends on modulating voltage manipulating concentration of charge carrier in doped silicon

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Comparison of lithium niobate and silicon substrate on phase shift and efficiency performance for mach-zehnder interferometer modulator

Summary form only given: We present photonic wire device structures based on silicon on insulator (SOI) - in particular tapered Bragg gratings. Different types of taper specification have been introduced to enable efficient coupling of light into the grating region. The structure has been simulated using the 2D FDTD method in the Fullwave software from Rsoftreg- and shows substantial improvement in reflectivity within the stop-band. Reductions in the spectral side-lobe levels have been obtained. In recent years, photonic wires have become one of the major fields of research due to their compactness and capability of reduced losses. Their high index contrast makes them suitable for design requirements such as sharp bends, T-junctions and Mach-Zehnder structures. The waveguide Bragg gratings have been widely studied and understood. They provide high optical confinement due to the high index contrast between the core and its surrounding cladding, which leads to a small volume and a compact structure. Photonic wires have great potential for applications such as distributed Bragg reflectors. wavelength division multiplexing and non-linear optics. Bragg gratings and waveguide micro-cavities have been realised at 1.55 mum with clear controllability of the stop band. 2D and 3D FDTD simulation methods have been studied and analysed recently for these structures, with relatively good agreement. Simulation of the first order tapered Bragg gratings has been carried out the using the Fullwave 2-D FDTD simulation tool. A rectangular recess structure was introduced into the sidewalls of the waveguide with 4-period tapered structures of various types at the input and the output of the grating. The modelled tapered Bragg grating waveguide has a 32 period grating (Lambda=360 nm), recess=250 nm and used a 500 nm width photonic wire with a 260 nm thick silicon (Si) core. The grating period is derived from the famous Bragg equation, Lambda=mlambda0/2neff where Lambda is a grating period, neff=effective index, lambda0=free space wavelength and m=1 for first order grating. This study shows that the tapering of the amplitude has increased the reflectivity to almost 95% for both linear and parabolic tapers. But the oscillations in the side lobe structure in the longer wavelength region are large, due to the length of the grating region. Non-symmetrical behaviour between the side- lobes is observed, but the situation is further improved by means of tapering both the amplitude and the phase of the gratings. A reflectivity of >96% is observed, together with reduction of the side lobe oscillations in the longer wavelength region by almost 50%. Photonic wire tapered Bragg grating based on silicon on insulator have been successfully simulated- and show an improvement of reflectivity by almost 10%, as compared with the classical waveguide Bragg Grating. 2D FDTD simulations are preferable because of the reduced time consumption and memory requirements, when compared with 3D FDTD simulation. They show good a predictable trend for the stop band. We now plan to investigate different types of taper structure (i.e. linear, parabolic and cosine) using 3D FDTD simulation. Comparisons will be made to determine the accuracy of the 2D and 3D FDTD simulations and how these compare with the results of measurements

Design, Fabrication and Measurement of SOI-based photonic wire devices, including Bragg-grating structures

This work reports the application of carbon dots (CDs) cooperated with silver nanotriangular (AgNT) for the enhancement of creatinine detection of localized surface plasmon resonance biosensors. Creatinine is detected through the hydrogen bonding between the functional group of the sensing material creatinine. Carbon dots were successfully synthesized via a hydrothermal process using citric acid and ethylenediamine as precursors. AgNT was successfully synthesized via the direct chemical reduction method. The appearance of four peaks of carbon dots in UV-visible analysis, at 206, 228, 242, and 384 nm. In PL spectroscopy, the peak of carbon dots, silver nanotriangular (AgNT), and carbon dot/silver nanotriangular (CDs/AgNT) composite that dissolves in an aqueous solution appeared at 451, 447, and 446 nm each. The carbon dots cooperate with silver nan-otriangular before the sensor performance analysis. In localized surface plasmon resonance, the carbon dot/silver nanotriangular exhibits the sensitivity of 4.07 nm(mg/dL)-1 respectively.

Carbon Dots/Silver Nanotriangular Based Localized SPR Biosensors for Enhancement of Creatinine Detection

For environmental and human health reasons, developing an efficient organic small molecule sensor (OSMS) with rapid, sensitive, and selective sensing of ammonia (NH3) is critical. This paper describes a Py-based gas sensor for ammonia (NH3) detection and sensing at RT. Spectroscopic and structural characterizations validated the effective production of the Py. The Py-based constructed device structure sensor displayed remarkable detection sensitivity for NH3 at concentrations as low as 10 ppm, The appealing sensing properties of NH3 at room temperature are owing to H2O pre-doping in Py and NH3 interaction to terminal electron-rich ester groups on pyerene molecule. In contrast to earlier reported organic conducting materials sensor demonstrated very long-term stability and high sensitivity to NH3, as well as surprising selectivity towards ammonia when compared to formaldehyde, methanol, ethanol, and benzene. The Py-based sensor demonstrated good ammonia detection capability, with maximum 60% response which could be helpful in real world applications.

Ultra-Sensitive Pyerene Based of Room Temperature (RT) Organic Small Molecule Ammonia Detecting Sensor

We present experimental and simulation studies of the strong coupling (SC) between a collection of identical Frenkel excitons and the surface plasmon (SP). We introduced a novel organic material to observe experimentally the SC regime. We demonstrate that the behaviour of the SC regime can be simulated by dipole sources in the simulation model to imitate the Frenkel excitons. The simulation model demonstrated a close match to the experimental observation, indicating the applicability of the proposed model.

Ahmad Rifqi Md Zain

Papers

Comparison of lithium niobate and silicon substrate on phase shift and efficiency performance for mach-zehnder interferometer modulator

Design, Fabrication and Measurement of SOI-based photonic wire devices, including Bragg-grating structures

Carbon Dots/Silver Nanotriangular Based Localized SPR Biosensors for Enhancement of Creatinine Detection

Ultra-Sensitive Pyerene Based of Room Temperature (RT) Organic Small Molecule Ammonia Detecting Sensor

Experimental and simulation studies of strong coupling between Frenkel excitons and surface plasmon