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A novel temperature-insensitive tilt sensor is proposed based on two fiber Bragg gratings (FBGs), which were embedded in a cylindrical cantilever-based pendulum in two orthogonal planes. Tilt-induced bending of the pendulum changes bandwidths and hence reflected optical powers of the two FBGs. Intensity-measurements of two-dimensional (2D) tilt angles can be realized without temperature dependence. Theoretical analysis and experimental verification have been carried out. Sensitivity of 42.97 nW/° with measurement accuracy of 0.27° has been achieved over a range up to ±15°. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:344-346, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27281 [ABSTRACT FROM AUTHOR]

Abstract: A finite-difference time-domain (FDTD) method combined with a periodic boundary condition is used to analyze the diffraction efficiency of an etched diffraction grating (EDG) demultiplexer coated with a metallic film at the backside. The numerical results show that the diffraction loss is mainly due to the scattering effect of shaded facets of a metal-coated grating at both the polarizations. However, the same shaded facets can produce a higher loss for a TM polarization than that for a TE polarization, which induces a higher polarization dependent loss (PDL) of the demultiplexer. [Copyright &y& Elsevier]

Highlights • To achieve a high sensitivity, the cascaded two Fabry-Perot interferometers sensor with the Vernier effect was proposed. • For the intensity interrogation, the sensor system only required a broadband light source and the photo detector. • The reaction between the Streptomycin monoclonal antibody and Streptomycin-BSA was measured by the sensor for the biosensing application. Abstract In this paper, a novel high-sensitivity optical sensor based on cascaded two Fabry-Perot interferometers (FPIs) has been investigated theoretically and experimentally. In order to improve the sensitivity, the two FP interferometers were designed with slightly different free spectrum ranges (FSRs) to produce Vernier effect. The experimental results showed that the sensitivity of the sensor is 23,794.6 nm/RIU for the wavelength interrogation and 4602.3 dB/RIU for the intensity interrogation, much higher than that of the conventional sensors for the bulk refractive index (RI) sensing. Finally, the reaction between Streptomycin monoclonal antibody and Streptomycin-BSA was measured, showing a great potential for low-cost and portable systems in biochemical sensing. [ABSTRACT FROM AUTHOR]

We propose a photonic time-stretched analog-to-digital converter (PTS-ADC) based on dispersion-tunable chirped fiber Bragg grating (CFBG), by demonstrating a economical ADC system with seven different stretch factors. The stretch factors are tunable by changing the dispersion of CFBG, in order to obtain different sampling points. Accordingly, the total sampling rate of the system can be improved. Only a single channel is required to increase the sampling rate and achieve the effect of multi-channel sampling. Finally, seven groups of different stretch factors ranging from 1.882 to 2.206 are obtained, which are equivalent to seven groups of different sampling points. We successfully recover the input radio frequency (RF) signals with frequencies from 2 GHz to 10 GHz. In addition, the sampling points are increased by 14.4 times and the equivalent sampling rate is increased to 288 GSa/s. The proposed scheme is suitable for commercial microwave radar systems, which can obtain a much higher sampling rate at a low cost.

Objective: This study aimed to assess whether a 5-year follow-up education intervention changed the risk for fragility fractures and increased bone mineral density (BMD) in elderly women with osteoporosis., Methods: This randomized controlled trial included 104 women who were hospitalized or visited a specialist for osteoporosis care at Sichuan Translational Medicine Research Hospital in China from October 2013 to June 2014. The patients were randomly assigned to either an education intervention group (n = 52) or a control group (n = 52). The intervention was conducted by an endocrinologist who provided the intervention group with personized recommendations. All participants were followed for 5 years., Results: Compared with the control group, the patients in the intervention group had a lower risk for fragility fracture, lower pain score, higher BMD at the greater trochanter of the femur, total hip and the first lumbar vertebra, together with higher compliance with anti-osteoporosis drug regimens and higher intake of vitamin D supplements (all P <.05). After adjustment for history of fracture, calcium consumption, age and body mass index (BMI), the association of change in BMD and pain score and the medication possession ratio (MPR) of anti-osteoporosis drugs were both significantly different (P < .05, P < .001, respectively). In subgroup analysis by past fractures, patients who experienced post-fractures were more likely to experience refracture (P < .05)., Conclusions: The personalized education intervention by endocrinologists can significantly increase the BMD of the greater trochanter of the femur and reduce pain scores in elderly women with osteoporosis, suggesting that this education intervention may serve as an important addition to standard anti-osteoporosis treatment.

All-inorganic perovskite CsPbBr 3 -Cs 4 PbBr 6 composite nanocrystals (NCs) were synthesized via a convenient solution process without inert gas protection and systematically studied as green phosphors for light emitting diode (LED) applications. While colloidal composite NCs emit green color with an emission peak at around 515 nm, their thin films on top of blue GaN chips exhibit a redshift of ∼15-20 nm due to subsequential aggregation in solid state. The Commission Internationale De I'eclairage (CIE) chromaticity coordinates of the green LEDs assembled by composite NCs reached (0.201, 0.746) with nearly 100% green ratio. Moreover, the pure green LED displayed a luminous efficiency of 45 lm W -1 under 10 mA driving current. The colloidal CsPbBr 3 -Cs 4 PbBr 6 composite NCs have the photoluminescence quantum yield (PLQY) as high as 74%. The high PLQY originates from cubic CsPbBr 3 NCs well passivated by the zero-dimensional Cs 4 PbBr 6 matrix, substantially suppressing the nonradiative recombination. The comparison between the green LEDs fabricated with pure and composite perovskites imply that the CsPbBr 3 -Cs 4 PbBr 6 composites with higher quantum yield could be an effective way to get the brightness and the stability of pure green LEDs.