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Y P Tao, J G Wu, H S Ma, S L Shao, L L Zhang, B Gao, H X Li
Objective: To investigate the causes of 30-day unplanned revision surgery following one-stage posterior vertebral column resection (PVCR) for severe spinal deformity and the methods of prevention and management. Methods: A total of 112 severe deformity patients underwent one-stage PVCR for surgical treatment in the 306(th) Hospital of People's Liberation Army from May 2010 to December 2015 were retrospectively reviewed. Six patients required reoperation within 30 days after PVCR, including 2 males and 4 females with average age of 21 years (ranging from 12 to 38 years)...
March 1, 2017: Zhonghua Wai Ke za Zhi [Chinese Journal of Surgery]
Volodymyr V Multian, Fillip E Kinzerskyi, Anna V Vakaliuk, Liudmyla M Grishchenko, Vitaliy E Diyuk, Olga Yu Boldyrieva, Vadim O Kozhanov, Oleksandr V Mischanchuk, Vladyslav V Lisnyak, Volodymyr Ya Gayvoronsky
The present study is objected to develop an analytical remote optical diagnostics of the functionalized carbons surface. Carbon composites with up to 1 mmol g(-1) of irreversibly adsorbed bromine were produced by the room temperature plasma treatment of an activated carbon fabric (ACF) derived from polyacrylonitrile textile. The brominated ACF (BrACF) was studied by elastic optical scattering indicatrix analysis at wavelength 532 nm. The obtained data were interpreted within results of the thermogravimetric analysis, X-ray photoelectron spectroscopy and temperature programmed desorption mass spectrometry...
December 2017: Nanoscale Research Letters
Xiao-Jing Han, Si-Bo Duan, Zhao-Liang Li
An analysis of the atmospheric impact on ground brightness temperature (Tg) is performed for numerous land surface types at commonly-used frequencies (i.e., 1.4 GHz, 6.93 GHz, 10.65 GHz, 18.7 GHz, 23.8 GHz, 36.5 GHz and 89.0 GHz). The results indicate that the atmosphere has a negligible impact on Tg at 1.4 GHz for land surfaces with emissivities greater than 0.7, at 6.93 GHz for land surfaces with emissivities greater than 0.8, and at 10.65 GHz for land surfaces with emissivities greater than 0.9 if a root mean square error (RMSE) less than 1 K is desired...
February 20, 2017: Optics Express
Xiaodong Zhang, Shuangyan He, Afshin Shabani, Peng-Wang Zhai, Keping Du
In examining the dependence of the sea surface reflectance of skylight ρs on sky conditions, wind speed, solar zenith angle, and viewing geometry, Mobley [Appl. Opt.38, 7442 (1999).10.1364/AO.38.007442] assumed ρs is independent of wavelength. Lee et al. [Opt. Express18, 26313 (2010).10.1364/OE.18.026313] showed experimentally that ρs does vary spectrally due to the spectral difference of sky radiance coming from different directions, which was ignored in Mobley's study. We simulated ρs from 350 nm to 1000 nm by explicitly accounting for spectral variations of skylight distribution and Fresnel reflectance...
February 20, 2017: Optics Express
Aya Nozaki, Masaya Mitobe, Fumio Okuyama, Yuji Sakamoto
Electro-holography can display images without inducing fatigue and three-dimensional (3D) sickness, i.e., visual discomfort due to viewing a stereoscopic display. Thus, this technology is expected to be applied to 3D media. However, there are no studies that have shown the agreement between the dynamic responses of accommodation and vergence to the reconstructed images of electro-holography and those to the real targets. This paper describes the measurement results of these responses using a developed system that can simultaneously measure the dynamic responses of accommodation and vergence...
February 20, 2017: Optics Express
Manon Rostykus, Ferréol Soulez, Michael Unser, Christophe Moser
Lensless quantitative phase imaging is of high interest for obtaining a large field of view (FOV), typically the size of the camera chip, to observe biological cell material with high contrast. It has the potential to be widely spread due to its inherent simplicity. However, the tradeoff is the added complexity due to the illumination. Current illumination systems are several centimeters away from the sample, use mechanics to obtain super resolution (i.e., smaller than the detector pixel size) or different illumination directions, and block the view to the sample...
February 20, 2017: Optics Express
J Réhault, R Borrego-Varillas, A Oriana, C Manzoni, C P Hauri, J Helbing, G Cerullo
We introduce a birefringent interferometer for Fourier transform (FT) spectroscopy in the mid-infrared, covering the vibrational fingerprint region (5-10 µm, 1000-2000 cm<sup>-1</sup>), which is crucial for molecular identification. Our interferometer employs the crystal calomel (Hg<sub>2</sub>Cl<sub>2</sub>), which combines high birefringence (n<sub>e</sub>-n<sub>o</sub>≈0.55) with a broad transparency range (0.38-20 µm). We adopt a design based on birefringent wedges, which is simple and compact and guarantees excellent delay accuracy and long-term stability...
February 20, 2017: Optics Express
Zhengyong Liu, Lin Htein, Lun-Kai Cheng, Quincy Martina, Rob Jansen, Hwa-Yaw Tam
In this paper, we present a miniature fluidic flow sensor based on a short fiber Bragg grating inscribed in a single mode fiber and heated by Co<sup>2+</sup>-doped multimode fibers. The proposed flow sensor was employed to measure the flow rates of oil and water, showing good sensitivity of 0.339 nm/(m/s) and 0.578 nm/(m/s) for water and oil, flowing at v = 0.2 m/s. The sensitivity can be increased with higher laser power launched to the Co<sup>2+</sup>-doped multimode fibers. A small flow rate of 0...
February 20, 2017: Optics Express
Urban Bitenc
Deformable mirrors (DMs) are used in adaptive optics for correcting optical aberrations: the DM surface can be deformed to compensate for them. Recently we reported the results on investigation of the stability of Alpao DMs, i.e. how accurately a DM surface shape can be maintained over minutes and hours without any optical feed-back. We observed a creep behavior of the DM surface and we presented a proof-of-concept software compensation for it, showing that very high stability is achievable. In this paper we develop a generalized creep compensation method that covers a wide range of DM use-cases and compensates for 90% - 95% of the creep observed...
February 20, 2017: Optics Express
Jianwei Chen, Hiu Hung Lee, Dongping Wang, Si Di, Shih-Chi Chen
We present a high-precision hybrid imprinting method to fabricate multi-layer micro-optical structures on nonplanar substrates using a custom-built vacuum imprinting system; with the application of kinematic couplings that align the flexible stamps in all six degrees of freedom, a cross-layer pattern registration precision of 400 nm has been achieved on nonplanar substrates. To demonstrate the precision and feasibility of the new process and instrument, we have designed and fabricated a multi-layer artificial compound eye (ACE) for multispectral imaging...
February 20, 2017: Optics Express
Rudolf Weber, Thomas Graf, Christian Freitag, Anne Feuer, Taras Kononenko, Vitaly I Konov
In any pulsed and repetitive laser process a part of the absorbed laser energy is thermalized and stays in the material as residual heat. This residual heat is accumulating from pulse to pulse, continuously increasing the temperature, if the time between two pulses does not allow the material to sufficiently cool down. Controlling this so-called heat accumulation is one of the major challenges for materials processing with high average power pulsed lasers and repetitive processing. Heat accumulation caused by subsequent pulses (HAP) on the same spot and heat accumulation caused by subsequent scans (HAS) over the same spot can significantly reduce process quality, e...
February 20, 2017: Optics Express
Justin Norman, M J Kennedy, Jennifer Selvidge, Qiang Li, Yating Wan, Alan Y Liu, Patrick G Callahan, McLean P Echlin, Tresa M Pollock, Kei May Lau, Arthur C Gossard, John E Bowers
High performance III-V lasers at datacom and telecom wavelengths on on-axis (001) Si are needed for scalable datacenter interconnect technologies. We demonstrate electrically injected quantum dot lasers grown on on-axis (001) Si patterned with {111} v-grooves lying in the [110] direction. No additional Ge buffers or substrate miscut was used. The active region consists of five InAs/InGaAs dot-in-a-well layers. We achieve continuous wave lasing with thresholds as low as 36 mA and operation up to 80°C.
February 20, 2017: Optics Express
E Al-Rawachy, R P Giddings, J M Tang
A DSP-based cross-channel interference cancellation (CCIC) technique with initial condition-free, fast convergence and signal modulation format independence, is experimentally demonstrated in a two-channel point-to-point digital filter multiple access (DFMA) PON system based on intensity-modulation and direct-detection (IMDD). The CCIC-induced transmission performance improvements under various system conditions are fully investigated for the first time. It is shown that with one iteration only the CCIC technique can achieve a reduction in individual OFDM subcarrier BERs of more than 1000 times, an increase in transmission capacity by as much as 19 times and an increase in optical power budget by as much as 3...
February 20, 2017: Optics Express
Minh A Tran, Tin Komljenovic, Jared C Hulme, M J Kennedy, Daniel J Blumenthal, John E Bowers
We present the first chip-scale "integrated optical driver" (IOD) that can interrogate with a sensing coil to realize an interferometric optical gyroscope. The chip comprises a light source, three photodiodes, two phase modulators and two 3-dB couplers within an area of 4.5 mm<sup>2</sup>. This allows for a significant reduction in size, weight, power consumption and cost of optical gyroscopes.
February 20, 2017: Optics Express
Wei Feng, Rui Shi, Chao Zhang, Tingting Yu, Dan Zhu
Hyperspectral imaging combining with skin optical clearing technique provides a possible way to non-invasively monitor hemodynamics of cutaneous microvessels. In order to estimate microvascular blood oxygen saturation, in this work, a lookup-table-based inverse model was developed to extract the microvascular optical and physiological properties using hyperspectral analysis. This approach showed a higher fitting degree than currently existing hyperspectral analysis methods (i.e. multiple linear regression and non-negative least square fit) in estimating blood oxygen saturation...
February 20, 2017: Optics Express
He Hao, Juanjuan Ren, Hongyi Chen, Iam Choon Khoo, Ying Gu, Qihuang Gong
The control and enhancement of the spontaneous emission (SE) of emitters embedded in subwavelength structures are fundamentally interesting and of practical interest. For example, in plasmonic lasers and on-chip single photon sources, a large SE rate and the active modulation of SE over a very broad spectral band are highly desired functionalities. In this paper, we demonstrate by an explicit theoretical calculation that a plasmonic waveguide cladded with liquid crystals (LCs) and low-index metamaterials can give rise to an enhancement in the intrinsic SE rate γ<sub>0</sub> of more than two orders of magnitude...
February 20, 2017: Optics Express
Ramraj Velmurugan, Jerry Chao, Sripad Ram, E Sally Ward, Raimund J Ober
Multifocal plane microscopy (MUM) can be used to visualize biological samples in three dimensions over large axial depths and provides for the high axial localization accuracy that is needed in applications such as the three-dimensional tracking of single particles and super-resolution microscopy. This report analyzes the performance of intensity-based axial localization approaches as applied to MUM data using Fisher information calculations. In addition, a new non-parametric intensity-based axial location estimation method, Multi-Intensity Lookup Algorithm (MILA), is introduced that, unlike typical intensity-based methods that make use of a single intensity value per data image, utilizes multiple intensity values per data image in determining the axial location of a point source...
February 20, 2017: Optics Express
Lisl Robertson Lain, Stewart Bernard, Mark W Matthews
The accurate description of a water body's volume scattering function (VSF), and hence its phase functions, is critical to the determination of the constituent inherent optical properties (IOPs), the associated spectral water-leaving reflectance, and consequently the retrieval of phytoplankton functional type (PFT) information. The equivalent algal populations (EAP) model has previously been evaluated for phytoplankton-dominated waters, and offers the ability to provide phytoplankton population-specific phase functions, unveiling a new opportunity to further understanding of the causality of the PFT signal...
February 20, 2017: Optics Express
Roland E Mainz, Giulio Maria Rossi, Giovanni Cirmi, Yudong Yang, Oliver D Mücke, Franz X Kärtner
We introduce a simple all-inline variation of a balanced optical cross-correlator (BOC) that allows to measure the arrival time difference (ATD), over the full Nyquist bandwidth, with increased common-mode rejection and long-term stability. An FPGA-based signal processing unit allows for real-time signal normalization and enables locking to any setpoint with an unprecedented accuracy of 0.07 % within an increased ATD range of more than 400 fs, resulting in attosecond resolution locking. The setup precision is verified with an out-of-loop measurement to be less than 80 as residual jitter paving the way for highly demanding applications such as parametric waveform synthesizers...
February 20, 2017: Optics Express
Andrea Bellucci, Ignacio Aedo, Paloma Díaz
Building and exploring physical user interfaces requires high technical skills and hours of specialized work. The behavior of multiple devices with heterogeneous input/output channels and connectivity has to be programmed in a context where not only the software interface matters, but also the hardware components are critical (e.g., sensors and actuators). Prototyping physical interaction is hindered by the challenges of: (1) programming interactions among physical sensors/actuators and digital interfaces; (2) implementing functionality for different platforms in different programming languages; and (3) building custom electronic-incorporated objects...
February 23, 2017: Sensors
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