Volume 7,Issue 5,2011 Table of Contents
2011, 7(5).
Abstract:
The goal of Optoelectronics Letters is to rapidly report original,new and important results in the fields of photonics and optoelectronics in English,to advance the international academic exchanges.Optoelectronics Letters pays a particularly attention to the cross topics between photonics and electronics.The scope of Optoelectronics Letters is as follows:Novel OE-devices and applications;New materials and functional components;Nano-structures and OE integration;Nano-quantum optoelectron
The goal of Optoelectronics Letters is to rapidly report original,new and important results in the fields of photonics and optoelectronics in English,to advance the international academic exchanges.Optoelectronics Letters pays a particularly attention to the cross topics between photonics and electronics.The scope of Optoelectronics Letters is as follows:Novel OE-devices and applications;New materials and functional components;Nano-structures and OE integration;Nano-quantum optoelectron
2011, 7(5):321-324.
Abstract:
SnO2 nanosheet films about 200 nm in thickness are successfully fabricated on fluorine-doped tin oxide (FTO) glass by a facile solution-grown approach. The prepared SnO2 nanosheet film is applied as an interfacial layer between the nanocrystalline TiO2 film and the FTO substrate in dye-sensitized solar cells (DSCs). Experimental results show that the introduction of a SnO2 nanosheet film not only suppresses the electron back-transport reaction at the electrolyte/FTO interface but also provides a...
SnO2 nanosheet films about 200 nm in thickness are successfully fabricated on fluorine-doped tin oxide (FTO) glass by a facile solution-grown approach. The prepared SnO2 nanosheet film is applied as an interfacial layer between the nanocrystalline TiO2 film and the FTO substrate in dye-sensitized solar cells (DSCs). Experimental results show that the introduction of a SnO2 nanosheet film not only suppresses the electron back-transport reaction at the electrolyte/FTO interface but also provides a...
2011, 7(5):325-329.
Abstract:
The GaAs based InGaAs metamorphic structures and their growth by molecular beam epitaxy (MBE) are investigated. The controlling of the source temperature is improved to realize the linearly graded InGaAs metamorphic structure precisely. The threading dislocations are reduced. We also optimize the growth and annealing parameters of the InGaAs quantum well (QW). The 1.3-μm GaAs based metamorphic InGaAs QW is completed. A 1.3-μm GaAs based metamorphic laser is reported. 更多还原
The GaAs based InGaAs metamorphic structures and their growth by molecular beam epitaxy (MBE) are investigated. The controlling of the source temperature is improved to realize the linearly graded InGaAs metamorphic structure precisely. The threading dislocations are reduced. We also optimize the growth and annealing parameters of the InGaAs quantum well (QW). The 1.3-μm GaAs based metamorphic InGaAs QW is completed. A 1.3-μm GaAs based metamorphic laser is reported. 更多还原
2011, 7(5):330-333.
Abstract:
An air-stable photovoltaic device based on znic oxide nanoparticles (ZNP) in an inverted structure of indium tin oxide (ITO)/ZnO/poly (3-hexylthiophene) (P3HT): [6,6]-phenyl C61-butyric acid methyl ester (PCBM)/MoO3/Ag is studied. We find that the optimum thickness of the MoO3 layer is 2 nm. When the MoO3 blocking layer is introduced, the fill factor of the devices is increased from 29% to 40%, the power conversion efficiency is directly promoted from 0.35% to 1.27%.The stability under ambient c...
An air-stable photovoltaic device based on znic oxide nanoparticles (ZNP) in an inverted structure of indium tin oxide (ITO)/ZnO/poly (3-hexylthiophene) (P3HT): [6,6]-phenyl C61-butyric acid methyl ester (PCBM)/MoO3/Ag is studied. We find that the optimum thickness of the MoO3 layer is 2 nm. When the MoO3 blocking layer is introduced, the fill factor of the devices is increased from 29% to 40%, the power conversion efficiency is directly promoted from 0.35% to 1.27%.The stability under ambient c...
2011, 7(5):334-336.
Abstract:
Optical models directly effect the irradiance distribution of observed surface. Traditionally, approximate Lambertian models are widely used in designing the light-emitting diodes (LED) arrays in spite of their errors compared with the experimental data. But now a novel LED optical model for uniform illumination system has been proposed, in which the curvefitting technique is used to reduce the inherited errors and modify those previous models. The points from the curve of the LED light intensit...
Optical models directly effect the irradiance distribution of observed surface. Traditionally, approximate Lambertian models are widely used in designing the light-emitting diodes (LED) arrays in spite of their errors compared with the experimental data. But now a novel LED optical model for uniform illumination system has been proposed, in which the curvefitting technique is used to reduce the inherited errors and modify those previous models. The points from the curve of the LED light intensit...
2011, 7(5):337-340.
Abstract:
A new type of solid-conversion gas detector is investigated for high energy X-ray industrial computed tomography (HECT). The conversion efficiency is calculated by using the EGSnrc Monte Carlo code on the Linux platform to simulate the transport process of photons and electrons in the detector. The simulation results show that the conversion efficiency could be more than 65%, if the X-ray beam width is less than about 0.2 mm, and a tungsten slab with 0.2 mm thickness and 30 mm length is employed...
A new type of solid-conversion gas detector is investigated for high energy X-ray industrial computed tomography (HECT). The conversion efficiency is calculated by using the EGSnrc Monte Carlo code on the Linux platform to simulate the transport process of photons and electrons in the detector. The simulation results show that the conversion efficiency could be more than 65%, if the X-ray beam width is less than about 0.2 mm, and a tungsten slab with 0.2 mm thickness and 30 mm length is employed...
2011, 7(5):341-345.
Abstract:
Frequency synthesizer is an important part of optical and wireless communication system. Low power comsumption prescaler is one of the most critical unit of frequency synthesizer. For the frequency divider, it must be programmable for channel selection in multi-channel communication systems. A dual-modulus prescaler (DMP) is needed to provide variable division ratios. DMP is considered as a critical power dissipative block since it always operates at full speed. This paper introduces a high spee...
Frequency synthesizer is an important part of optical and wireless communication system. Low power comsumption prescaler is one of the most critical unit of frequency synthesizer. For the frequency divider, it must be programmable for channel selection in multi-channel communication systems. A dual-modulus prescaler (DMP) is needed to provide variable division ratios. DMP is considered as a critical power dissipative block since it always operates at full speed. This paper introduces a high spee...
2011, 7(5):346-349.
Abstract:
We report a numerical method to analyze the fractal characteristics of far-field diffraction patterns for two-dimensional Thue-Morse (2-D TM) structures. The far-field diffraction patterns of the 2-D TM structures can be obtained by the numerical method, and they have a good agreement with the experimental ones. The analysis shows that the fractal characteristics of far-field diffraction patterns for the 2-D TM structures are determined by the inflation rule, which have potential applications in...
We report a numerical method to analyze the fractal characteristics of far-field diffraction patterns for two-dimensional Thue-Morse (2-D TM) structures. The far-field diffraction patterns of the 2-D TM structures can be obtained by the numerical method, and they have a good agreement with the experimental ones. The analysis shows that the fractal characteristics of far-field diffraction patterns for the 2-D TM structures are determined by the inflation rule, which have potential applications in...
2011, 7(5):350-353.
Abstract:
A simultaneous blue-light and red-light emitting glass of SrO-B2O3-P2O5 doped with Eu2O3 is prepared in air, and then heat-treated without any reductive reagent. A transition combination is found to consist of a band emission peaked around 430 nm and a series of line emission from 593 nm to 611 nm, corresponding to the typical 4f65d→ 4f7 transition of Eu2+ and 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions of Eu3+, respectively. Some unidentified crystals such as Sr (PO3)2 and SrB2O4 as hosts for Eu2...
A simultaneous blue-light and red-light emitting glass of SrO-B2O3-P2O5 doped with Eu2O3 is prepared in air, and then heat-treated without any reductive reagent. A transition combination is found to consist of a band emission peaked around 430 nm and a series of line emission from 593 nm to 611 nm, corresponding to the typical 4f65d→ 4f7 transition of Eu2+ and 5D0 → 7FJ (J = 0, 1, 2, 3, 4) transitions of Eu3+, respectively. Some unidentified crystals such as Sr (PO3)2 and SrB2O4 as hosts for Eu2...
2011, 7(5):354-357.
Abstract:
According to the perturbation theory, the coupled-mode equations for guided optical waves in the magneto-optical fiber Bragg gratings (MFBGs) under non-uniform magnetic field are derived. The equivalent relation between the magneticallyinduced non-uniform fiber Bragg grating (MnFBG) and the corresponding non-magnetic chirped grating is expressed and verified by the piecewise-uniform MFBG model under linear magnetic field. On the basis of the equivalent relation, the MnFBGs can be effectively inv...
According to the perturbation theory, the coupled-mode equations for guided optical waves in the magneto-optical fiber Bragg gratings (MFBGs) under non-uniform magnetic field are derived. The equivalent relation between the magneticallyinduced non-uniform fiber Bragg grating (MnFBG) and the corresponding non-magnetic chirped grating is expressed and verified by the piecewise-uniform MFBG model under linear magnetic field. On the basis of the equivalent relation, the MnFBGs can be effectively inv...
2011, 7(5):358-362.
Abstract:
In this work, the theoretical model of FBG when it is affected by double external variables (temperature and transverse pressure) and triple external variables (temperature, axial strain and transverse pressure) is deduced, respectively. The simulated results show that the properties of cross sensitivity would change in a certain regulation with the external effects and fiber parameters. At the same time, some valuable suggestions about how to improve the measurement accuracy are put forward as ...
In this work, the theoretical model of FBG when it is affected by double external variables (temperature and transverse pressure) and triple external variables (temperature, axial strain and transverse pressure) is deduced, respectively. The simulated results show that the properties of cross sensitivity would change in a certain regulation with the external effects and fiber parameters. At the same time, some valuable suggestions about how to improve the measurement accuracy are put forward as ...
2011, 7(5):363-366.
Abstract:
The high peak-to-average power ration (PAPR) values of optical orthogond frequency division multiplexing (OFDM) signal limit the system nonlinear tolerance (NLT). In this paper, a novel method based on Hadamard precoding is proposed to reduce the peak-to-average power ratio in optical direct detection OFDM system. The proposed scheme is successfully applied to an experimental system of optical direct-detection OFDM signal transmission through fiber. In this experiment, the 2.5 Gbit/s binary phas...
The high peak-to-average power ration (PAPR) values of optical orthogond frequency division multiplexing (OFDM) signal limit the system nonlinear tolerance (NLT). In this paper, a novel method based on Hadamard precoding is proposed to reduce the peak-to-average power ratio in optical direct detection OFDM system. The proposed scheme is successfully applied to an experimental system of optical direct-detection OFDM signal transmission through fiber. In this experiment, the 2.5 Gbit/s binary phas...
2011, 7(5):367-370.
Abstract:
In this paper we design a new kind of sinc-sampled fiber Bragg grating which is fabricated in high birefringence fiber (HBF). The sampled grating has two sets of reflection spectra along two perpendicular polarization directions. The grating’s channel number can be doubled approximately by designing the refractive index difference between the fast and slow axes of the fiber, which enhances the utilization ratio and reduces the claim for photosensitivity of the fiber. The group delay characterist...
In this paper we design a new kind of sinc-sampled fiber Bragg grating which is fabricated in high birefringence fiber (HBF). The sampled grating has two sets of reflection spectra along two perpendicular polarization directions. The grating’s channel number can be doubled approximately by designing the refractive index difference between the fast and slow axes of the fiber, which enhances the utilization ratio and reduces the claim for photosensitivity of the fiber. The group delay characterist...
14 An IIR adaptive electronic equalizer for polarization multiplexed fiber optic communication systems
2011, 7(5):371-375.
Abstract:
An electronic digital equalizer for polarization multiplex coherent fiber optic communication systems is designed to compensate polarization mode dispersion (PMD) and residual chromatic dispersion (CD) of transmission channel. The proposed equalizer is realized with fraction spaced infinite impulse response (IIR) butterfly structure with 21 feedforward taps and 2 feedback taps. Compared with finite impulse response (FIR) structure, this structure can reduce implementation complexity of hardware ...
An electronic digital equalizer for polarization multiplex coherent fiber optic communication systems is designed to compensate polarization mode dispersion (PMD) and residual chromatic dispersion (CD) of transmission channel. The proposed equalizer is realized with fraction spaced infinite impulse response (IIR) butterfly structure with 21 feedforward taps and 2 feedback taps. Compared with finite impulse response (FIR) structure, this structure can reduce implementation complexity of hardware ...
JIA Yong-po
,
YE Wei-lin
,
TIAN Chong-wen
,
QUAN Xiang-yin
,
WANG Jia-qi
,
SONG Zhan-wei
,
ZHENG Chuan-tao
2011, 7(5):376-379.
Abstract:
An OOK-NRZ visible light communication (VLC) system is designed by using a single white LED and a 550 nm visible photodetector. The emitting model of the single LED is established, and the general expression of the detector’s output signals under OOK modulation is deduced. With the selected LED, detector and other related parameters, the designed communication system is optimized and its performance is analyzed. The optimized communication distance between the LED and the detector is 0.54 m at t...
An OOK-NRZ visible light communication (VLC) system is designed by using a single white LED and a 550 nm visible photodetector. The emitting model of the single LED is established, and the general expression of the detector’s output signals under OOK modulation is deduced. With the selected LED, detector and other related parameters, the designed communication system is optimized and its performance is analyzed. The optimized communication distance between the LED and the detector is 0.54 m at t...
2011, 7(5):380-383.
Abstract:
A new displacement measurement system is described in this paper according to the basic principles of traditional lasertriangulation method. The range of the traditional measuring method is enlarged by measuring in sections. Three independent CCDs, which are distributed uniformly along the optical axis, are used to achieve subsection measurement. The planemirror is regarded as a virtual detector. When imaging beam is reflected by the plane mirror, the beam is imaged on theCC D. The designed syst...
A new displacement measurement system is described in this paper according to the basic principles of traditional lasertriangulation method. The range of the traditional measuring method is enlarged by measuring in sections. Three independent CCDs, which are distributed uniformly along the optical axis, are used to achieve subsection measurement. The planemirror is regarded as a virtual detector. When imaging beam is reflected by the plane mirror, the beam is imaged on theCC D. The designed syst...
2011, 7(5):384-388.
Abstract:
An open path atmospheric composition monitor is designed based on ultraviolet differential absorption technology.Dark current correction and diode response correction are used to improve the detection limit and Savitzky-Golay filter is used to improve the measurement accuracy.The experimental results show that the designed system has the ability to measure NO and NO 2 in real time with reasonable accuracy.The detection limit of the system is about 0.25 ppm for NO and 0.28 ppm for NO 2 .When the ...
An open path atmospheric composition monitor is designed based on ultraviolet differential absorption technology.Dark current correction and diode response correction are used to improve the detection limit and Savitzky-Golay filter is used to improve the measurement accuracy.The experimental results show that the designed system has the ability to measure NO and NO 2 in real time with reasonable accuracy.The detection limit of the system is about 0.25 ppm for NO and 0.28 ppm for NO 2 .When the ...
2011, 7(5):389-393.
Abstract:
A three-state protocol for the SARG04 decoy-state quantum key distribution(QKD)based on an unstable source is presented. The lower bound to the secure key generation rate is derived without using the basic hypothesis of the original decoy-state idea.The three-state SARG04 decoy-state protocol with an unstable parametric down-conversion source is considered in the simulation.The simulation results show that the protocol in this paper with an unstable source gives a key generation rate that is clo...
A three-state protocol for the SARG04 decoy-state quantum key distribution(QKD)based on an unstable source is presented. The lower bound to the secure key generation rate is derived without using the basic hypothesis of the original decoy-state idea.The three-state SARG04 decoy-state protocol with an unstable parametric down-conversion source is considered in the simulation.The simulation results show that the protocol in this paper with an unstable source gives a key generation rate that is clo...
2011, 7(5):394-396.
Abstract:
An experimental study of the optical phonons is presented for InAlN epilayers lattice-matched with GaN by means of Raman scattering,and theoretical simulations are done to investigate the zone-center optical phonons of InAlN alloy by using the modified random element isodisplacement(MREI)model.The calculated findings show that the LO and TO branches of InAlN crystal both exhibit nonlinear properties.A comparison is made between the theoretical results and the experimental data,and it shows that ..
An experimental study of the optical phonons is presented for InAlN epilayers lattice-matched with GaN by means of Raman scattering,and theoretical simulations are done to investigate the zone-center optical phonons of InAlN alloy by using the modified random element isodisplacement(MREI)model.The calculated findings show that the LO and TO branches of InAlN crystal both exhibit nonlinear properties.A comparison is made between the theoretical results and the experimental data,and it shows that ..
2011, 7(5):397-400.
Abstract:
By using the Collins diffraction formula and expanding the aperture function into a finite sum of complex Gaussian functions, an analytical formula of the time light intensity distribution for oblique Gaussian beams passing through a moving cat-eye optical lens and going back along the entrance way is deduced.By numerical computation,the variation laws of the time intensity distributions of the cat-eye reflected light with the viewing angle,imaging distance,aperture and instantaneous field of vi..
By using the Collins diffraction formula and expanding the aperture function into a finite sum of complex Gaussian functions, an analytical formula of the time light intensity distribution for oblique Gaussian beams passing through a moving cat-eye optical lens and going back along the entrance way is deduced.By numerical computation,the variation laws of the time intensity distributions of the cat-eye reflected light with the viewing angle,imaging distance,aperture and instantaneous field of vi..
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