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This study investigated the therapeutic activity of a series of chain thiophene photosensitizers (PS) using theoretical simulation approaches. Density functional theory and its time-dependent extension (DFT, TD-DFT) were used to calculate the parameters for the determination of various photophysical properties of PSs, such as electronic absorption spectrum, singlet-triplet state energy gap, and to discuss the electron-hole relationship between excited states and orbitals. The calculations show that these photosensitizers have a practical inter-system crossing (ISC) transition from the first singlet excited state to the lower triplet state excited state with sufficient energy to produce reactive oxygen species (ROS). These suitable properties make these series of PSs promising for photodynamic therapy (PDT) applications. these photosensitizer molecules in this work can provide a theoretical reference for further experimental researches.

A series of blue and green-emitting phosphorescent heteroleptic cyclometalated Ir(III) complexes with mesityl-phenyl-imidazole Ligand for organic light-emitting devices are investigated theoretically to explore their electronic structures, spectroscopic properties and the application value for organic light emitting devices. The geometries, electronic structures, lowest-lying singlet absorptions, and triplet emissions of Ir(mpim)3, and the theoretically designed models Ir(F-mpim)3, Ir(F2-mpim)3, (mpim)2Ir(acac), (F-mpim)2Ir(acac), (F2-mpim)2Ir(acac), (mpim)2Ir(tpip), (F-mpim)2Ir(tpip), (F2-mpim)2Ir(tpip), are investigated with Density Functional Theory (DFT) approaches, where mpim denotes 1-mesityl-2-phenyl-1H-imidazole, F-mpim denotes 2-(4-fluorophenyl)-1-mesityl-1H-imidazole, F2-mpim denotes 2-(2,4-difluorophenyl)-1-mesityl-1H-imidazole, acac denotes acetylacetonate, and tpip denotes tetraphenylimido-diphosphinate.

A series of heteroleptic cyclometalated Ir (III) complexes, which are used for OLED application, were investigated by DFT and TD‐DFT method. The frontier molecular orbital character and charge transfer character shown that they have the advantages of low efficiency roll‐off, which is a “stumbling block” in the process of OLED solid‐lighting's development. Namely, means the materials will play an important role in the journey development of OLED.

A series of blue phosphorescent heteroleptic cyclometalated Ir(III) complexes with mesitylphenyl-imidazole ligands for organic light-emitting devices have been theoretically studied. We want to find their electronic structures, spectroscopic properties, and application value for organic light-emitting devices. (fppz)2Ir(acac), (fppz)2Ir(tpip), (dfbdp)2Ir(fppz), (F-fppz)2Ir(acac), (F-fppz)2Ir(tpip), and (dfbdp)2Ir(F-fppz) are investigated with DFT and TD-DFT approaches, where, for (fppz)2Ir(acac), (fppz denotes 2-(5-(trifluoromethyl)-4H-pyrazol-3-yl)pyridine, and acac denotes acetylacetonate); for (fppz)2Ir(tpip), tpip denotes tetraphenylimido-diphosphinate; and, for (F-fppz)2Ir(acac) and (F-fppz)2Ir(tpip), F-fppz denotes 2-(5-fluoro-4H-pyrazol-3-yl)pyridine.

An effective improvement on the empirical orthogonal function (EOF)–based bias correction method for seasonal forecasts is proposed in this paper, by introducing a stepwise regression method into the process of EOF time series correction. Using 30-year (1981–2010) hindcast results from IAP AGCM4.1 (the latest version of this model), the improved method is validated for the prediction of summer (June–July–August) rainfall anomalies in Southeast China. The results in terms of the pattern correction coefficient (PCC) of rainfall anomalies shows that the 30-year-averaged prediction skill improves from 0.01 to 0.06 with the original correction method, and to 0.29 using the improved method. The applicability in real-time prediction is also investigated, using 2016 summer rainfall prediction as a test case. With a PCC of 0.59, the authors find that the new correction method significantly improves the prediction skill; the PCC using the direct prediction of the model is −0.04, and using the old bias correction method it is 0.37.

Based on coupled mode theory, electro-optic modulation theory, and microring resonance theory, a structural model was proposed for a polymer parallel channel microring resonator (MRR) electro-optic switch array, and in the meantime, with a resonance wavelength of 1550 nm, optimization design and simulation analysis were conducted on a eight microrings and nine channels switch array. According to the results of numerical simulation, the free spectral range (FSR) was about 17.71 nm and the 3-dB bandwidth of the output spectrum was about 0.18 nm when the cross-section size of the waveguide core was 1.5 × 1.5 μm2, the confining layer between the waveguide core and the electrode was 2.0 μm thick, the metal electrode was 0.05 μm thick, the coupling gap between the microring and the channel was 0.1 μm, and the microring radius was 12.76 μm. When the voltage of 7 V was applied on microring i of the device in turn, the output optical power Pi of horizontal channel i was the largest, and the output optical power of all the other channels became very small, which meant that the switching function of horizontal channel i was fulfilled. The insertion loss of the device was within a range of 1.39–8.17 dB, and the crosstalk was smaller than −4.8 dB.

As an important precursor, the dinuclear [{Ir(C^N)2Cl}2] (C^N = ppy, dfppy) derived luminescent complex is nearly non-emissive at room temperature, but two similar chlorine-bridged dinuclear complexes [{Ir(ppy)2}2Cl(BTA)] (1) and [{Ir(dfppy)2}2Cl(BTA)] (2) (BTA = 1,2,3-benzotriazole) are proved to be bright. Herein, we report both complexes 1 and 2 from the viewpoint of experiment and theory. In order to characterize the two complexes better, single-crystal X-ray diffraction of 1 and 2 was carried out to determine their molecular structure. The emission spectra at room temperature (298 K) was measured, and the emission quantum yields for 1 and 2 in degassed CH2Cl2 were also given. The combined density functional theory (DFT) and time-dependent DFT (TDDFT) study was employed to gain insights into the electronic structure and radiative decay of these systems.

We proposed a 1×N-channel cross-grid microring resonator array (MRRA) model according to the coupled mode theory (CMT), electro-optic (EO) modulation theory, and microring resonance theory. This model integrates wavelength division multiplexing and switching functions. When this model is subjected to an operating voltage, the horizontal channel outputs a new resonance wave. As an example, the 1×8-channel cross-grid MRRA with 1550-nm central wavelength and 0.8-nm wavelength spacing is used to analyze its transmission characteristics. The simulation results show that the resonant wavelength in the horizontal channels shifts when the sectional size of the waveguide core, the buffer layer thickness between the waveguide core and electrode, electrode thickness, and coupling gap between the microring and channel are 1.5 × 1.5 μ m 2 , 2.0 μm, 0.05 μm, and 0.1μm, respectively; this shift also occurs when the switching voltage changes from 0 to 21.3V. Thus, resonance wavelength conversion with 0.8-nm wavelength spacing can be achieved in the same horizontal channel.

Herein, a cross-grid microring resonator electro-optic switching array model is proposed on the basis of the coupled mode theory, electro-optic modulation theory, and microring resonance theory. The proposed device has N+1 horizontal channels, N vertical channels, and 2N microrings with equal radii. By applying an operating voltage to the microrings in the array unit in various ways, the switching function of the N+1 horizontal channel can be realized. Taking the structure of 9 × 8 channels as an example, the output spectrum, insertion loss, crosstalk, extinction ratio, and other characteristics of this switching array device under a resonant wavelength of 1550 nm are simulated and analyzed.

A series of blue phosphorescent heteroleptic cyclometalated Ir(III) complexes with mesitylphenyl-imidazole ligands for organic light-emitting devices have been theoretically studied. We want to fin...

By means of the interpolation and iteration methods to deal with the rate equations and the light propagation equations for the Er3+/Yb3+ codoped waveguide amplifier (EYCDWA), the gain characteristics in the forward, backward, and bidirectional pumped styles are analyzed. In order to obtain high gain, some parameters such as waveguide length, dopant concentration, pump power, and signal power are optimized. The results show that the pump power and signal power are about 50 mW and 1 mW, respectively, the gain is about 6.5 dB for the 2.0 cm-long EYCDWA with an Er3+ ion concentration of 1.5 × 1026 m–3 and Yb3+ ion concentration of 1.9 × 1027 m–3. Moreover, the upconversion is investigated for the designed device.

An arrayed waveguide grating (AWG) multiplexer with flat spectral response has been designed and fabricated by using FPE polymer materials. Experimental results show that the central wavelength is 1550.86 nm, and 3-dB bandwidth is about 0.478 nm, insertion loss is 10.5 dB. Simulated results show that fabrication processing result in the shift of the transmission spectrum compared with the device theoretically designed. Furthermore, the transmission characteristics are discussed, and some efficient ways are reported.

Parameter optimization is performed, transmission characteristics are analyzed, and effects of fabrication errors are investigated for a lateral coupling microring resonator (MRR). Simulated results show that the fabrication errors result in the shift and shape change of the transmission spectrum compared with the designed case without errors. In order to reduce spectral changes, an efficient compensation method of fabrication errors is investigated.

In order to improve the detecting efficiency of the Hall vehicle speed sensor, an improved detection system was presented in this paper. This system was consists of five parts of system manager, A/D converter, D/A converter, voltage comparator, and a high-speed programmable counter array. The quality of Hall vehicle speed sensor online was evaluated, and the statistical result was graphically displayed by PC. Compared with the synchronous detection of digital storage oscilloscope, it is shown that the detecting accuracy of the system can then meet the requirements of industrial production, and will be suitable for mass production.

The system had achieved a wireless data communication function using AVR SCM as a control center and basing on radio frequency identification technology. The transmitting terminal of system produces a high frequency signal through capacitance connecting three point type oscillator. And the encoded signal will be transmitted after high-frequency carrier modulated. While after the receiving terminal receive the signal through antenna, and the signal after a series processes including amplification, detection, rectification, voltage comparison will be processed by SCM. The system includes temperature humidity sensor, clock generator chip, photosensitive element, could detect the surrounding environment signal and wireless transmit. The paper elaborates the soft and the hardware realizing specific course of the wireless transmission system. It has an important meaning for the wireless transmission technique.

A hall speed sensor detection system is designed in this paper. The system consists of the controlling circuit part, the detecting circuit part and the microcomputer part. The system’s structure is simple. It has the advantages such as lower cost, intuitive display and user-friendly. The detecting accuracy can meet the requirements of industrial production, and be suitable for mass production.

All the effects of manufacturing errors on transmission spectrum are analyzed for a vertical coupling microring resonator (MRR). Results show that the core refractive index, core thickness and radius errors of ring result in central wavelength shift of the transmission spectrum, and the central deviation and thickness between the ring and channel lead to nonresonant light intensity change. In order to obtain satisfactory spectrum for a fabricated MRR device, some allowed manufacturing errors are discussed, and the accumulation and compensation of manufacturing errors are investigated.

Single-chip AT89C2051 as the main-control component of the device, we designed a digital thermometer from the aspects of hardware, it with the aid of temperature sensor DS18B20, the device used single bus technology to detect the ambient temperature (analogue) is converted into digital quantity, it was accepted, processed, judged by single-chip microcomputerand then control and display. The temperature measured range in - 30 °C to + 120 °C, the accuracy class + 0.5 °C, four LED Nixie tube as display mode.

A 33×33 polymer arrayed waveguide grating (AWG) multiplexer is optimized and fabricated. This device is made of polymeric materials named 2,3,4,5,6-pentafluorostyrene-co-glycidylmethacrylate (PFS-co-GMA). The central wavelength and wavelength spacing are designed to be 1550.918 and 0.8 nm, respectively. The calculated results are: the 3-dB bandwidth is about 0.24 nm, insertion loss is about 8.4 dB and crosstalk is −33.7 dB. The corresponding measured results are: the center wavelength is about 1550.85 nm, wavelength channel spacing is about 0.81 nm, 3-dB bandwidth is about 0.35 nm, crosstalk is about −20 dB, insertion loss is between 10.4 dB for the central port and 11.9 dB for the edge ports.

Based on the transmission theory, parameter optimization is performed, and effects of fabrication errors on transmission characteristics are analyzed for a 33×33 polymer arrayed waveguide grating (AWG) multiplexer around the central wavelength of 1550.918 nm with the wavelength spacing of 0.8 nm. Simulated results show that fabrication errors result in the shift of the transmission spectrum, and lead to the increase of the crosstalk compared with the device theoretically designed. Furthermore, accumulation and compensation of fabrication errors are investigated. In order to realize the normal demultiplexing of the fabricated AWG device, the allowed fabrication errors are discussed.

By employing perturbation theory, a technique called the 'equivalent rectangular waveguide method' is proposed for analyzing the transmission characteristics of polymeric arrayed waveguide grating (AWG) multiplexers with non-ideal core cross sections, which are modeled by the 'tanh' function. Simulation results show that the non-ideal core cross sections cause the shift of the transmission spectrum, and result in the increase of crosstalk compared with the device originally designed with exact rectangular core cross sections. In order to eliminate the shift of the transmission spectrum, reduce the crosstalk and further realize accurate demultiplexing, the redesign of the AWG device is carried out.

In terms of the coupled mode theory, novel formulations of the transfer functions are presented for a series-cascaded microring resonator (MRR) array. Using these formulas, transmission characteristics are analyzed and some parameters are optimised for such a polymer device. Simulation results show that when several microrings are serially cascaded to form a MRR array, the passband becomes steep, and the nonresonant light and the crosstalk become weak.

In terms of the coupled mode theory and transfer matrix technique, novel formulas of the amplitude coupling ratios and transfer functions are presented for a series-coupled microring resonator (MRR) array. By using these formulas, parameters are optimized, and transmission characteristics including the transmission spectrum and the insertion loss are analyzed for a SiN/SiO2 series-coupled MRR array on Si substrate. The box-like spectral response is successfully obtained owing to the proper selection of the amplitude coupling ratio between the channel and the ring, and that between adjacent rings, as well as the number of series-coupled rings.

Novel formulas of amplitude coupling ratio and transmission functions are presented for a smooth square microring resonant (MRR) wavelength multiplexer. By using these formulas, transmission characteristics are analyzed and some parameters are optimized for such a 1 × 8 polymeric device around the central wavelength of 1550.92 nm with the wavelength spacing of 1.6 nm. In the design of the device, by using the smooth squares, a thicker coupling layer is obtained, and by resonating the light at different resonant orders in different filter elements, the ring radius increment is increased sufficiently, which is of benefit to the fabrication of the device. When the amplitude coupling ratio is 0.2, the 3-dB bandwidth of the spectral response is about 0.2 nm; the ratio between −1 dB and −10 dB bandwidths is about 0.2; the insertion loss is less than 1.33 dB; and the crosstalk is below −21 dB for every vertical output channel of the device.

An efficient technique is proposed to flatten the spectral response of an arrayed waveguide grating (AWG) multiplexer. By subtracting an increment from the length difference of odd arrayed waveguides and by adding the same increment to that of even arrayed waveguides, a boxlike spectral response can be obtained. The simulated result for a 17 × 17 polymer AWG shows that the boxlike spectral response has a 3-dB bandwidth of 0.49 nm, and the crosstalk is about or less than −28 dB for every output channel. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 916–919, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21518

By means of the coupled mode theory and transfer matrix technique, a method is presented for analyzing the bending coupling between straight and bent rectangular waveguides, or between two bent rectangular waveguides. Calculations show that an effective coupling region exists around the central coupling point, in which the bending coupling appears, beyond which the bending coupling is very weak, and the propagation power in each waveguide becomes constant. When the bending radius becomes larger or the central coupling gap becomes smaller, this effective coupling region becomes wider, in which the coupling behavior becomes stronger.

In terms of the coupled mode theory and transfer matrix technique, novel formulas of the amplitude coupling ratio and transfer functions are presented for a parallel-cascaded microring resonator array (PCMRR). By using these formulas, effects of structural parameters, especially the ring spacing, on the spectral response are analyzed for this kind of polymer device. The box-like spectral response is successfully obtained due to the proper selection of the ring spacing, amplitude coupling ratio and the number of rings.

In this article, the RIE process has been improved, a polymer arrayed waveguide grating (AWG) multiplexer with flat spectral response have been designed and fabricated using FPE polymer materials. Using the steam-redissolution technique, the insertion loss and the crosstalk have been reduced. Experimental results show that the central wavelength is 1550.86 nm, and 3-dB bandwidth is about 0.478 nm, insertion loss is 10.5 dB, crosstalk is about −20.5 dB. The insertion loss of an AWG device is reduced by about 3 dB for the central channel and 4.5 dB for the edge channels, and the crosstalk is reduced by 1.5 dB after the steam-redissolution. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2199–2201, 2013

A series of heteroleptic cyclometalated Ir (III) complexes for OLEDs application have been investigated theoretically to explore their electronic structures and spectroscopic properties. The geometries, electronic structures, and the lowest-lying singlet absorptions and triplet emissions of (piq)2Ir(acac) (labeled 1) and theoretically designed models (piq)2Ir(dpis) (labeled 2), (4Fpiq)2Ir(dpis) (labeled 3), (4F5M-piq)2Ir(dpis) (labeled 4), (4,5-2F-piq)2Ir(dpis) (labeled 5) and (5-F-piq)2Ir(dpis) (labeled 6) were investigated with density functional theory (DFT)-based approaches, where, piq = 1-phenylisoquinolato, acac = acetylacetonate and dpis = diphenylimidodisilicate. Their structures in the ground and excited states have been optimized at the DFT/B3LYP/LANL2DZ and TDDFT/B3LYP/LANL2DZ levels, and the lowest absorptions and emissions were evaluated at B3LYP and M062X level of theory, respectively. Furthermore, the energy-transfer mechanism of these complexes also be analyzed here, and the result shown that the complexes 1–6 are having the low efficiency roll-off property. Except that, the oscillator strength analyze shown that the complexes 2–6, which were designed by theory, are suitable for OLED since their high oscillator strength property.

A 17 × 17 polymer arrayed waveguide grating (AWG) multiplexer with flat spectral response have been designed and fabricated by using FPE polymer materials.The measured results are as: the center wavelength is 1550.83 nm, wavelength channel spacing is 0.8 nm, 3-dB bandwidth is about 0.476 nm, insertion loss is 13∼15 dB, and crosstalk is about −21 dB. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1653–1655, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25277

A 33×33 thermo-optically tunable arrayed-waveguide-grating (AWG) has been fabricated by using the poly (2, 3, 4, 5, 6-pentafluorostyrene-co-glycidylmethacrylate) (PFS-co-GMA). The technological process of the fabrication of the device is described, and the measured results are presented. The measured spacing of the wavelength channel is about 0.81 nm, the 3-dB bandwidth is about 0.35 nm, the crosstalk is about −20 dB, and the insertion loss is between 10.4 dB for the centre port and 11.9 dB for the edge port. The measured thermo — optical tunable shift is about −0.12 nm/K. The measured center wavelength is 1545.21–1551.81 nm in the temperature range from 10°C to 65°C, and the tuning range is 6.6 nm.

In the fabrication of a polymeric arrayed waveguide grating (AWG) device, the cores of the channels and the arrayed waveguides exhibit smooth trapezoid cross-sections instead of originally designed rectangular ones after reactive ion etching and steam-redissolution. By employing the Marcatili theory, a method called “equivalent energy flow method” is proposed for analyzing the transmission characteristics of the polymeric AWG with trapezoid core cross-sections. The AWG parameters have been fixed, and a 17×17 polymeric AWG multiplexer has been designed and fabricated. Experimental results show that the central wavelength is 1550.83 nm, and the bandwidth at half maximum is about 0.478 nm; insertion loss is 10 to 13 dB, and crosstalk is about −21 dB .

A 33×33 thermo-optic tunable arrayed waveguide grating (AWG) is fabricated using the poly (2,3,4,5,6-pentafluorostyrene-co-glycidylmethacrylate) (PFS-co-GMA). The fabrication process of the device is depicted, and the measured results are presented. The measured insertion loss is between 8.5 dB for the central channel and 10 dB for the edge channels, the crosstalk is below −20 dB, the wavelength channel spacing is 0.8 nm, and the 3-dB bandwidth is 0.35 nm. The measured wavelength/temperature shift rate is about −0.12 nm/K. The central wavelength is 1545.21 to 1551.81 nm in the temperature range from 10 to 65°C. The tuning range is −6.6 nm.

In terms of the coupled mode theory, novel formulas of the transfer functions are presented for a microring resonator array, which consists of multiple series-cascaded filter elements, and each of them contains double parallel-cascaded identical microrings. By using these formulas, we can analyze transmission characteristics for such a polymer device. Simulated results show that when some parameters are selected properly, the box-like spectral response can be formed, which is flat and steep, and the sidelobes and the cross talk can be dropped efficiently. The effects of manufacturing tolerances on the transmittance are discussed, which result in the shift of the transmission spectrum of the device.