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Based on Jones matrices theory, the paper researches the error source and action mechanism of the polarized interferometer in nanometer level measurement. It opens the door for selecting optical component, adjusting light set-up and compensating error. According to the theoretical analysis, the main reason that causes error is degeneration of polarization that the imperfect performance of optical components and imperfect adjusting bring. Especially the different delay angle happens more obviously. The characteristic of the passive homodyne laser interferometer based on the polarized phase-shift is that the output of interferometer is four-channel signals in quadrature. Using this characteristic, through strict selecting and fine adjusting components and differential signal processing, the interferometer can perform nanometer measurement.

Based on Jones matrices theory, the error source and action mechanism of polarized interferometer using four-channel orthogonal signals in nanometer level measurement are researched. It opens a door for selecting optical components, adjusting light set-up and compensating error.The mechanism of nonlinear errors and the variance law of nonlinear errors in laser interferometer, which is caused by nonideal factors of 1/4 wave plates or 1/2 wave plate or all of them, based on polarized phase-shift technology. In this paper, every single error on the polarized interferometer is discussed with the isolation of each wave plate, so that the character of nonlinear error will be reached with composite error. In the experiments, difference delay angle error of two 1/4 wave plates and location angle error is -5°∼5°in interferometer. The aim of this paper is to realize the mechanism of nonlinear errors and the varying rule of nonlinear errors in laser interferometer. All above provide error remove or compensation for laser interferometer in nanometer level measurement with theoretical foundation and search after application.

Based on two-core optical fiber, compact in-fiber integrated Michelson and Mach-Zehnder interferometers are proposed and demonstrated, which have the potential to be exploited in a variety of wide sensing applications.

We propose and demonstrate a novel surface plasmon resonance (SPR)-sensing approach by using the fundamental mode beam based on a twin-core fiber (TCF). Although normally in a fiber SPR sensor, a multimode fiber (MMF) has often been used to improve the coupling efficiency; for improving fiber SPR sensor sensitivity, single-mode beam is optimal. We provide a novel method to employ the single (fundamental)-mode beam to SPR sense based on the TCF. We grind the TCF tip to be a frustum wedge shape, and plate a 50-nm sensing gold film on the end face, and two 500-nm reflected gold films on the side faces of the wedge tip. By using this new configuration, we reduce the mode noise effectively and get a high testing sensitivity (the testing highest sensitivity reaches to 6463 nm/RIU). This SPR probe can be applied in a microfluidic chip and monitors the refractive index (RI) charges of the flow liquid in the microfluidic channel in real-time. The probe successfully monitors the refractive index of liquid ranged from 1.3333 to 1.3706, and the average sensitivity reaches to 5213 nm/RIU in the solution, which is much higher than most multimode SPR systems.

We propose an ultra-simple dual-channel configuration for simultaneously evaluating two branches of a multifunctional integrated optic chip (MFIOC). In the configuration, the MFIOC is employed as a beam splitter to construct the demodulation interferometer together with a 2×2 fiber coupler. Interference happens between polarization modes traveling through different channels of the MFIOC. The cross-couplings of each channel are respectively characterized by the interference peaks which distribute on opposite sides of the central interference peak. Temperature responses of the MFIOC are experimentally measured from −40°C to 80°C. Results show that the proposed configuration can achieve simultaneous dual-channel transient measurements with resolution of −90 dB and dynamic range of 90 dB. In addition, the two channels of the configuration have consistent measuring performance, and the two branches of the MFIOC have different responses to temperature variation.

In recent years, the mobile metallo-β-lactamase (MBL) genes have been found to correspond to one of the most important resistance characters identified in Gram-negative bacteria, severely affecting clinical chemotherapy and threatening public health. The prevalence of mobile MBL genes and their flanking regions in Gram-negative bacteria from diseased pigs in China was investigated. A total of 334 lung samples from diseased pigs were screened for Gram-negative bacteria classified as non-susceptible to meropenem (MIC≥4 mg·L-1). Six isolates, including three Escherichia coli, two Acinetobacter baumanii and one A. calcoaeticus, exhibited MBL production and carried the blaNDM-1 gene. S1-PFGE and Southern blot analysis showed that the blaNDM-1 gene was located on the chromosome of one A. baumanii isolate and on plasmids of various sizes in the other five isolates. MIC testing using broth microdilution revealed that all blaNDM-1-carrying isolates and some of their transconjugants exhibited resistance to almost all β-lactams tested. Whole genome sequencing revealed that the flanking region of the blaNDM-1 gene from all porcine isolates had high levels of similarity with the corresponding regions in human isolates. One porcine E. coli isolate carrying blaNDM-1 was typed as ST48, a common sequence type in human E. coli isolates. These results suggest the possibility of human-to-food animal transfer of blaNDM-1-producing E. coli, highlighting the need for surveillance of carbapenemase producers among bacteria from food animals. In addition, the prudent use of antimicrobial agents to decrease the opportunities for co-selection of carbapenemase genes in food animals is also urgently needed.

A simple method for coupling between a single-core single-mode fiber and a multicore single-mode fiber is proposed and demonstrated. An effective coupling approach is based on a process of standard splicing and tapering between the single-core single-mode fiber and the multicore single-mode fiber.

The optimization of parameters for dual fiber optical tweezers is presented in this paper. Mode transmission properties are analyzed theoretically and characteristics of the optical field in tapered fiber are numerically simulated using FDTD method. The optimization of fiber's parameters such as the taper angle, radius of the fiber tip-lens and cladding radius at the tip of the tapered fiber is discussed in detail for the dual fiber optical tweezers. It is indicated that, for a common use, the taper angle should be as small as possible and the micro lens should be fabricated at the tip of the taper where the cladding is polished close to the fiber core. Experiments were done to investigate structural parameters including the arranged angle and the horizontal distance between the two fiber ends. Results indicate that the transverse trapping force is enhanced as the arranged angle reducing and there is an optimal horizontal distance between two fiber ends.

By standard splicing and tapering approach, a simple coupling method between single core single mode fiber and multicore single mode fiber has been proposed and demonstrated.

A fiber optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core is investigated.

A fiber optic force sensor is demonstrated based on a fused tapered fiber probe. By way of comparing the value of Brownian motion force with the trapping force, the Brownian motion force can be measured.

By embedding copper nanoparticles into poly(3,4-thylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) layers, the power conversion efficiency of organic bulk-heterojunction solar cell using poly(3-hexylthiophene) (P3HT) was increased from 3.58% to 3.96%, and that of the device based on poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7) was increased from 6.79% to 7.43%. The copper nanoparticles enhanced light harvesting efficiency because of their localized surface plasmon resonance effects. This improved short circuit current densities, the dominant reason for the improvement in performance. Our results indicate that copper nanoparticles are cost-effective plasmonic materials for organic bulk-heterojunction solar cells as compared with gold and silver nano-structures.

The combined two-ring-resonator schemes of fiber optic gyroscope are developed and demonstrated. The two-ring topology structure has been classified 2 kinds: two-ring in series and in parallel. The cavity lengths L1 and L2 of the two-ring-resonator are chosen as 623m and 1260m, respectively. A theoretical model of the two-ring Rayleigh backscattering fiber optic gyroscope which including the Sagnac effect is established. The experimental results are agreement with the theoretical prediction.

The robot, which is used for high building cleaning, hoists frictionally up and down along wall by means of the friction between two friction-wheels mounted on both sides of the frame and steel ropes which are suspended on the top of the building. In order to keep the frame in horizontal so that the robot can work smoothly, the two hoist mechanisms on both sides of the frame must be run synchronously. This paper discusses the design of the detector, which is used to measure the declining angle of the frame caused by nonsynchronal running of hoisting mechanisms, and fuzzy controller, which is used to harmonize the friction-hoisting mechanisms. The result of experiment shows that fuzzy controller can keep hoisting mechanisms running synchronously and hold the frame's posture in horizontal and the method is feasible and satisfied.

Ketamine may be advantageous for anesthesia of patients with sepsis caused by gram-negative bacteria, because ketamine may suppress LPS-induced production of proinflammatory cytokines, such as TNFalpha and IL-6. NFkappaB is an important transcription factor that is involved in the post-transcriptional regulation of mRNA expression for several immunoinflammatory mediators in response to endotoxemia. This study examined the effect of ketamine on NFkappaB activation and TNFalpha production in rat peripheral blood mononuclear cells (PBMC). The PBMC were incubated in the presence or absence of LPS and with graded concentrations of ketamine. The culture supernatants and cells were collected for each group and duration of incubation. Activation of NFkappaB was determined by electrophoretic mobility shift assay (EMSA), and the expression of IkappaBalpha, its inhibitor, in PBMC was analysed by Western blotting. TNFalpha levels in the supernatants were measured using a specific enzyme-linked immunosorbent assay (ELISA). LPS stimulation of rat PBMC increased TNFalpha production and NFkappaB activation, with corresponding loss of IkappaBalpha. Ketamine significantly reduced the LPS-induced NFkappaB activation and inhibited TNFalpha production in a dose-dependent manner. These in vitro findings suggest that ketamine is a potent inhibitor of NFkappaB activation and cytokine production in rat PBMC.

We fabricate and experimentally demonstrate a hybrid structured Fabry-Perot interferometer (FPI) embedded in the middle of a fiber line for simultaneous measurement of axial strain and temperature. The FPI is composed of a silica-cavity cascaded to a spheroidal air-cavity, both of which are formed in a hollow annular core fiber (HACF). The fabrication process of the FPI includes only a fusion splice between a single-mode fiber and a HACF and several electrical arc discharges at the HACF near the splice point. Experimental results show that the strain and temperature sensitivities of the air-cavity can be 5.2 pm/με and 1.3 pm/C°, respectively, and those of the silica-cavity can be 1.1 pm/με and 13 pm/C°, respectively. The different sensitivities of silica-cavity and air-cavity to strain and temperature enable us to implement simultaneous sensing in strain and temperature.

We find that the doping of Cr2O3 nanoparticles into organic bulk-heterojunction solar cells leads to the power conversion efficiency improvements of 15.9%–22.8%, which are larger than or comparable to those obtained using other metal oxide nanostructures in previous studies. The light absorptions at long-wavelength regions and the electron mobilities are enhanced; these enhancement increased the short-circuit current and fill factor. The increased shunt resistance suggests that the hole leakage current may be suppressed. This suppression subsequently enhances the fill factor. Thus, the incorporation of Cr2O3 nanoparticles is a simple and efficient technique for improving bulk-heterojunction devices.

The use of 1,8-diiodooctane (DIO) as a solvent additive in poly[N-9′-heptadecanyl-2,7-carbazole-alt-5, 5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT)-based bulk-heterojunction solar cells increased the power conversion efficiency (PCE) by 20.9%. This improvement was due to the increase in the fill factor and open-circuit voltage (Voc), which compensated for the decrease in the short-circuit current (Jsc). DIO had the opposite effect, increasing Jsc and decreasing Voc, in the devices using other low-band gap polymers. The best sample in this study showed a PCE of 6.27% and Voc of 939 mV, indicating that the fabricated device is an efficient solar cell with a high Voc close to 1 V.

We demonstrate trapped yeast cell axial-position adjustment without moving the optical fiber in a single-fiber optical trapping system. The dynamic axial-position adjustment is realized by controlling the power ratio of the fundamental mode beam (LP01) and the low-order mode beam (LP11) generated in a normal single-core fiber. In order to separate the trapping positions produced by the two mode beams, we fabricate a special fiber tapered tip with a selective two-step method. A yeast cell of 6 μm diameter is moved along the optical axis direction for a distance of ∼3 μm. To the best of our knowledge, this is the first demonstration of the trapping position adjustment without moving the fiber for single-fiber optical tweezers. The excitation and utilization of multimode beams in a single fiber constitutes a new development for single-fiber optical trapping and makes possible more practical applications in biomedical research fields.

A fiber optic integrated modulation-depth-tunable modulator based on a type of hollow optical fiber with suspended core is proposed and investigated. We synthesized magnetic fluid containing superparamagnetic Fe(3)O(4) nanoparticles and encapsulated it in the hollow optical fiber as the cladding layer of the suspended core by fusing the hollow optical fiber with the multimode optical fibers. The light with a wavelength of 632.8 nm is coupled in and out of the modulating element by a tapering technique. Experimental results show that the light attenuation in the system can be greatly influenced by only 2.0×10(-2) μL of the magnetic fluid under different magnetic field strengths. The saturated modulation depth is 43% when the magnetic field strength is 489 Oe. The response time of the system is120 ms. Significantly, this work presents information for the development of all-fiber modulators, including other integrated electro-optic devices, such as optical switch, optical fiber filter, and magnetic sensors utilizing the special structure of this hollow optical fiber with suspended core and superparamagnetic magnetic fluid.

We have improved power conversion efficiencies of organic bulk-heterojunction solar cells with the active layer composed of poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) by inserting a PCBM layer between the active layer and adjacent Al cathode. This improvement is mainly due to the increase in short-circuit current, which prevails over the changes in other parameters. The largest improvement of 11.7% is obtained at the PCBM thickness of 10 nm, while further increasing of the thickness degrades the fill factor and eventually induces S-kinks in the current-voltage characteristics. We discuss possible models explaining the efficiency variations with the PCBM thickness and the occurrence of the S-kinks.

By splicing and tapering at the fusion point of one-core single-mode fiber and three- or four-core single-mode fiber, an effective bitapered fiber coupling technique is implemented. Based on the beam propagation method, the bitapered coupling characteristics between the one-core fiber and the multicore single-mode fiber are simulated and analyzed. The theoretical prediction is confirmed by the experimental results, and the difference between the simulation and the experimental results is also discussed.

We present an abruptly tapered twin-core fiber optical tweezers, which is fabricated by fusing and drawing the twin-core fiber. In the twin-core fiber, the two beams are guided by the tapered fiber. At the end of the fiber tip, a larger converge angle between the two beams are made due to the abrupt tapered shape, which is formed a fast divergent optical field. The microscopic particle trapping performance of this special designed tapered twin-core fiber tip is investigated. The functionality of the proposed novel twin-core fiber optical tweezers is extended since an in-fiber integrated Mach-Zehnder interferometer has been used to control orientation of the trapped particle. The distribution of the optical field emerging from the tapered fiber tip is simulated based on the beam propagation method (BPM). By using this two-beam combination technique, a strong enough gradient forces well is obtained for microscopic particles trapping in three dimensions. The abruptly tapered twin-core fiber optical tweezers is rigid and easy to handle, especially useful for building up a multi-tweezers system for trapping and manipulating micro-scale particles.

A Brownian motion force measurement fiber optic probe is fabricated and demonstrated. The specially designed abrupt tapered fiber tip can be used to trap small particles. By way of comparing the value of Brownian motion random force with the trapping force exerted on the same particle at the ambient temperature T, the Brownian motion force can be measured.

A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.