Journals >Optoelectronics Letters
Contents
2019
Volume: 15 Issue 4
16 Article(s)
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Simulated and experimental study on temperature induced lens focal shifts
Xiao-zhu LIU, Li-na LIU, Jian-biao ZHOU, Liang SUN... and Yan-mei LIANG|Show fewer author(s)
Optical lenses used in high temperature environment are usually affected by thermal lenses problems, but it is difficult to evaluate their focal shifts in practical applications. A three-dimensional single-lens model based on finite element solver was built to evaluate the focal shift in this study, when the temperaturOptical lenses used in high temperature environment are usually affected by thermal lenses problems, but it is difficult to evaluate their focal shifts in practical applications. A three-dimensional single-lens model based on finite element solver was built to evaluate the focal shift in this study, when the temperature of surface was raised from the initial temperature to the specified temperature. An experimental method based on a Hartmann-Shack wavefront sensor was proposed to verify the rationality of the model. The nearly same results between simulations and experiments for N-BK7 and fused silica were obtained, which proves that it is feasible to analyze focal shifts of optical lenses by simulation methods..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 245 (2019)
Design and study of a long-wavelength monolithic high-contrast grating resonant-cavity-enhanced photodetector
Kun ZENG, Xiao-feng DUAN, Yong-qing HUANG, Kai LIU, and Xiao-min REN
Novel construction of a resonant-cavity-enhanced photodetector (RCE-PD) with monolithic high-contrast grating (HCG) is proposed to overcome the difficulty of fabricating a high reflective mirror of RCE-PD at 1 550 nm. In this structure, HCG serves as the top mirror of the RCE-PD, whereas InGaAs serves as a sacrificial Novel construction of a resonant-cavity-enhanced photodetector (RCE-PD) with monolithic high-contrast grating (HCG) is proposed to overcome the difficulty of fabricating a high reflective mirror of RCE-PD at 1 550 nm. In this structure, HCG serves as the top mirror of the RCE-PD, whereas InGaAs serves as a sacrificial layer to achieve monolithic integration. During the bandwidth optimization, the ratio of the thickness of the total intrinsic region and the absorption layer is introduced to realize the simultaneous optimization of the thickness of spacing layers and absorption layer. After structural optimization, the quantum efficiency of the device with diameter of 20 μm is 82% at 1 550 nm, and the 3-dB bandwidth is 34 GHz at a bias of 3 V..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 250 (2019)
Design and analysis method of moire magnifier based on depth cues from disparity
Chun-bao OUYANG, Gang LIU, Ying XIONG, and Yang-chao TIAN
Several methods have been developed to design and analyze moire magnifier, but these methods are all lack of quantitative consideration on the depth of moire imaging. In this paper, a new design method for moire magnifier based on depth cues from disparity is proposed. By using of the proposed method, the period magnifSeveral methods have been developed to design and analyze moire magnifier, but these methods are all lack of quantitative consideration on the depth of moire imaging. In this paper, a new design method for moire magnifier based on depth cues from disparity is proposed. By using of the proposed method, the period magnification, the rotation angle of moire pattern can also be calculated, and the moire depth can be analyzed, too. According to the design and analysis results using MATLAB, the period of arrays and the cross angle are the important influence factors as the moire pattern above or below the microlens array. Moreover, with our 3D design method, we can design different moire magnifier with different size, direction angle and depth of moire pattern as required..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 255 (2019)
Fabrication and characterization of annealed proton exchanged long period waveguide grating in x-cut LiNbO3
Ai-ling ZHANG, Bo GENG, Li-yue HAO, and Dan LI
In this paper, a long-period waveguide grating was fabricated in x-cut lithium niobate substrate by patterned annealed proton exchange waveguide fabrication process. The waveguide mode characteristic was evaluated using a charge-coupled device (CCD) camera. It shows that the waveguide is single mode transmission at a wIn this paper, a long-period waveguide grating was fabricated in x-cut lithium niobate substrate by patterned annealed proton exchange waveguide fabrication process. The waveguide mode characteristic was evaluated using a charge-coupled device (CCD) camera. It shows that the waveguide is single mode transmission at a wavelength of 1 550 nm. The transmission spectra of the long period waveguide gratings were measured by optical spectrum analyzer (OSA) and show an extinction ratio of ~17 dB and a 3 dB bandwidth of ~10 nm at the resonant wavelength. The resonant wavelength moves toward to the long wavelength direction as the waveguide width-difference increases in the same period, and also shifts toward to the long wavelength direction with the increase of the period in the case of the same waveguide width-difference. The method of fabricating a long period waveguide grating based on a patterned annealed proton exchange technique simplifies the fabrication process, and at the same time, reduces the fabrication cost..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 260 (2019)
Effect of adhesive type on the sensitivity coefficient of FBG sensor bonded on the surface of CFRP
Heng TIAN, Dong-guang LIU, Yan-ping WANG, and Qing-lin WANG
In this paper, the effects of three types of commonly used adhesives were studied via experiment and simulation. The results show that the strain sensitivity of fiber Bragg grating (FBG) sensor is about 1.201 pm/με and the effects of three adhesives of epoxy resin, AB glue and 502 glue with the same thickness and lengtIn this paper, the effects of three types of commonly used adhesives were studied via experiment and simulation. The results show that the strain sensitivity of fiber Bragg grating (FBG) sensor is about 1.201 pm/με and the effects of three adhesives of epoxy resin, AB glue and 502 glue with the same thickness and length on sensitivity coefficients of FBG sensors are 99.20%, 93.80% and 96.50%, respectively. Finally, the sensitivity coefficient of the simulated FBG sensor is the same as the test result by ANSYS modeling..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 264 (2019)
Hybrid plasmonic label-free multi-analyte refractive index sensor
R. Kishore K., Singh Utkarsh, N. Ayyanar, G. Thavasi Raja, and S. Sanathanan M.
We propose a label-free refractive index sensor based on hybrid plasmonic resonator which consists of silver split-ring resonator and photonic waveguide. The finite difference time domain evaluation of the design exhibit strong field confinement at the center of the ring and introduces tunable and sensitive notches in We propose a label-free refractive index sensor based on hybrid plasmonic resonator which consists of silver split-ring resonator and photonic waveguide. The finite difference time domain evaluation of the design exhibit strong field confinement at the center of the ring and introduces tunable and sensitive notches in the transmission spectrum. The planar tunable architecture which performs well over the range of micro fluid detection, holds the promise of developing multi-analyte label-free biosensors and compactness towards a complete on-chip integrated sensing system. The performance of the proposed refractive index sensor is evaluated by placing different analytes such as saline water and ethanol at the center of the hybrid plasmonic ring which exhibits sensitivity of 847.50 nm·RIU-1 with a figure of merit of 563.25 RIU-1..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 269 (2019)
Influence of Yb2O3 on the 1.53 μm spectroscopic properties in Er3+/Ce3+ co-doped TeO2-WO3-Na2O-Nb2O5 glasses
Shi-chao ZHENG, Zhong-jian KANG, Chang-chao LI, and Ya-xun ZHOU
The Yb2O3 component was introduced into the Er3+/Ce3+ co-doped tellurite glasses with the composition of TeO2-WO3-Na2O-Nb2O5 to study the effect of Yb3+ on the 1.53 μm spectroscopic properties of Er3+. The X-ray diffraction (XRD) curve and Raman spectrum were measured to investigate the structure nature of synthesized The Yb2O3 component was introduced into the Er3+/Ce3+ co-doped tellurite glasses with the composition of TeO2-WO3-Na2O-Nb2O5 to study the effect of Yb3+ on the 1.53 μm spectroscopic properties of Er3+. The X-ray diffraction (XRD) curve and Raman spectrum were measured to investigate the structure nature of synthesized tellurite glasses. The absorption spectrum, upconversion emission spectrum and fluorescence spectrum were measured to evaluate the improved effect of Yb3+ concentration on the 1.53 μm band fluorescence of Er3+. Results of the measured 1.53 μm band fluorescence intensity show a significant improvement with the increase of Yb3+ concentration, while the total quantum efficiency reveals a similar increasing trend. The results of the present work indicate that Er3+/Ce3+/Yb3+ tri-doped tellurite glass has good prospect as a promising gain medium applied for the 1.53 μm broadband amplifier..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 273 (2019)
Means and verification of broadcast technology applied to laser transmission on horizontal link
Yi-ning MU, Shuai WANG, Guo-zhen LIU, Chun-yang LIU... and Yan ZHU|Show fewer author(s)
At present, there has been great progress in the field of the point-to-point laser communication technology, in other words, the traditional laser communication technology has been advanced day by day. Furthermore, in order to search for an effective means of achieving localized laser broadcasting communication within At present, there has been great progress in the field of the point-to-point laser communication technology, in other words, the traditional laser communication technology has been advanced day by day. Furthermore, in order to search for an effective means of achieving localized laser broadcasting communication within a limited range, an effective method of horizontal link laser broadcasting communication is presented, and the corresponding verifiable broadcast communication system is designed. In addition, the laser broadcasting is systematically studied by one physical model built at the optimal distribution of optical power. First of all, the theoretical model of laser beam expansion and the theoretical model of parallel light curtain are made comparisons and analyzed from the angle of attenuation of optical power, and the optical power loss model of the parallel light curtain is established as a result. Secondly, combined with the theory of optical imaging transformation based on Gaussian beam, the field distribution of far field of parallel light curtain is simulated by one leading optical and illumination design software and the relation between the filed distribution of far field of light curtain and the distance of transmission is revealed. Finally, the superiority and feasibility of the parallel light curtain theory model are verified by field communication experiments in different information channels..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 277 (2019)
Image transmission in an OFDM VLC system using symbol scrambling and chaotic Walsh-Hadamard precoding
Zhong-peng WANG, Zhuo-ying YE, Xiu-min WANG, and Zhi-nian ZHAI
An image secure transmission scheme combining symbol scrambling and chaotic Wahsh-Hardmard precoding is proposed in orthogonal frequency division multiplexing (OFDM)-based visible light communication (VLC) system. In the proposed scheme, a two-dimensional (2D) logistic-sine-coupling map (LSCM) is employed to generate tAn image secure transmission scheme combining symbol scrambling and chaotic Wahsh-Hardmard precoding is proposed in orthogonal frequency division multiplexing (OFDM)-based visible light communication (VLC) system. In the proposed scheme, a two-dimensional (2D) logistic-sine-coupling map (LSCM) is employed to generate two chaotic sequences. One is used to scramble the 16 quadrature amplitude modulation (QAM) symbols, and the other is used to scramble the rows of standard Walsh-Hadamard transform (WHT). The simulation results show that the proposed scheme can not only reduce the peak-average-power ratio (PAPR) but also achieve the image secure transmission over OFDM-based VLC systems..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 284 (2019)
Timing synchronization algorithm based on FH sequence for coherent optical OFDM systems with carrier frequency offset
Li LI, Wang YAO, Li HAN, and Gui-jun HU
A novel symbol timing synchronization algorithm based on Frank-Hermiller (FH) sequence is proposed for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) systems with carrier frequency offset. The timing synchronization is realized by using only one training symbol which is composed of conjugated symA novel symbol timing synchronization algorithm based on Frank-Hermiller (FH) sequence is proposed for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) systems with carrier frequency offset. The timing synchronization is realized by using only one training symbol which is composed of conjugated symmetric sequences. The timing estimation of the proposed algorithm is robust to poor frequency offset. The proposed algorithm is shown to eliminate the timing sidelobes of Park’s algorithm and has a more accurate timing estimation. In the condition of frequency offset, the timing metric of the proposed method still maintains its peak value at the correct timing point, while the values are almost zero at all other positions..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 288 (2019)
A new construction method of QC-LDPC codes with low error floor based on EETS and Zig-Zag
De-meng ZHENG, Jian-guo YUAN, Hong-sen WANG, Fu-zhuo FAN, and Meng YUAN
Aiming at the problem that quasi-cyclic low density parity check (QC-LDPC) codes may have the error floor in the high signal to noise ratio (SNR) region, a new construction method of the QC-LDPC codes with the low error floor is proposed. The basic matrix of the method is based on the progressive edge growth (PEG) algoAiming at the problem that quasi-cyclic low density parity check (QC-LDPC) codes may have the error floor in the high signal to noise ratio (SNR) region, a new construction method of the QC-LDPC codes with the low error floor is proposed. The basic matrix of the method is based on the progressive edge growth (PEG) algorithm and the improved eliminate elementary trapping sets (EETS) algorithm so as to eliminate the elementary trapping sets in the basic matrix, then the Zig-Zag method is used to construct the cyclic shift matrix which is used to extend the basic matrix in order to construct the parity check matrix. The method not only can improve the error floor in the high SNR region, but also can flexibly design the code length and code rate. The simulation results show that at the bit error rate of 10-6, the PEG-trapping-Zig-Zag (PTZZ)-QC-LDPC(3024,1512) codes with the code rate of 0.5, compared with the PEG-Zig-Zag (PZZ)-QC-LDPC(3024,1512) codes and the PEG-QC-LDPC(3024,1512) codes, can respectively improve the net coding gain of 0.1 dB and 0.16 dB. The difference among the bit error rate performance curves will become better with the increase of the SNR. In addition, the PTZZ-QC-LDPC(3024,1512) codes have no error floor above the SNR of 2.2 dB..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 292 (2019)
Real-time 850 nm multimode VCSEL to 1 550 nm single mode VCSEL data routing for optical interconnects
Isoe G. M., R. Leitch A. W., and Gibbon T. B.
Short-reach optical interconnects among massive serves in data centers have attracted extensive research recently. Increasing capacity, cost and power efficiency as well as wavelength switching between data center network nodes are still key challenges for current optical interconnects. In this work, we experimentally Short-reach optical interconnects among massive serves in data centers have attracted extensive research recently. Increasing capacity, cost and power efficiency as well as wavelength switching between data center network nodes are still key challenges for current optical interconnects. In this work, we experimentally demonstrate the real-time inter- mode optical wavelength switching technique, for high-speed wavelength flexible data center interconnects. A 10 Gbit/s 1 550 nm single mode vertical cavity surface emitting laser (VCSEL) is optically injected and used to control a 10 Gbit/s multimode VCSEL carrier at 850 nm. Results show that a clearly open eye diagram is achieved at back-to-back analysis, implying a successful wavelength switch and error-free operation at 10 Gbit/s. A fully optical wavelength conversion of a multimode VCSEL operation at 850 nm using a single mode VCSEL subject to external optical injection at 1 550 nm is reported. This work opens new perspectives towards the development of a cost effective high-speed real-time inter-band wavelength switching technique between servers and network devices operating at different transmission windows at network nodes, for current and future optical interconnects..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 297 (2019)
A new post-coding approach for PAPR reduction in DC-biased optical OFDM systems
Sharifi Abbas Ali
The high peak-to-average power ratio (PAPR) is one of the main drawbacks in orthogonal frequency division multiplexing (OFDM) communication systems, which also exists in the optical OFDM (O-OFDM) systems. In this letter, a new approach based on the discrete Hartley transform (DHT) post-coding technique is proposed to rThe high peak-to-average power ratio (PAPR) is one of the main drawbacks in orthogonal frequency division multiplexing (OFDM) communication systems, which also exists in the optical OFDM (O-OFDM) systems. In this letter, a new approach based on the discrete Hartley transform (DHT) post-coding technique is proposed to reduce PAPR of an O-OFDM signal in visible light communication systems. The proposed method is compared with Walsh-Hadamard transform (WHT) and discrete cosine transform (DCT) techniques in terms of PAPR reduction and bit error rate (BER) performance. Experimental results indicate that the proposed DHT post-coding method remarkably reduces the PAPR of an OFDM signal for optical intensity modulated direct detection systems without any corruption in the BER performance..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 302 (2019)
Final optics damage online inspection in high power laser facility
Fu-peng WEI, Feng-dong CHEN, Jun TANG, Zhi-tao PENG, and Guo-dong LIU
For the laser-induced damage (LID) in large-aperture final optics, we present a novel approach of damage online inspection and its experimental system, which solves two problems: classification of true and false LID and size measurement of the LID. We first analyze the imaging principle of the experimental system for tFor the laser-induced damage (LID) in large-aperture final optics, we present a novel approach of damage online inspection and its experimental system, which solves two problems: classification of true and false LID and size measurement of the LID. We first analyze the imaging principle of the experimental system for the true and false damage sites, then use kernel-based extreme learning machine (K-ELM) to distinguish them, and finally propose hierarchical kernel extreme learning machine (HK-ELM) to predict the damage size. The experimental results show that the classification accuracy is higher than 95%, the mean relative error of the predicted LID size is within 10%. So the proposed method meets the technical requirements for the damage online inspection..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 306 (2019)
Quantitative analysis of multicomponent mud logging gas based on infrared spectra
Li-mei SONG, Su-qing GUO, Yan-gang YANG, Qing-hua GUO... and Hui XIONG|Show fewer author(s)
This work deals with quantitative analysis of multicomponent mud logging gas based on infrared spectra. An accurate analysis method is proposed by combining a genetic algorithm (GA) and a radial basis function neural network (RBFNN). The GA is used to screen the infrared spectrum of the mixed gas, while the selected spThis work deals with quantitative analysis of multicomponent mud logging gas based on infrared spectra. An accurate analysis method is proposed by combining a genetic algorithm (GA) and a radial basis function neural network (RBFNN). The GA is used to screen the infrared spectrum of the mixed gas, while the selected spectral region is used as the input of the RBFNN to establish a calibration model to quantitatively analyze the components of logging gas. The analysis results demonstrate that the proposed GA-RBFNN performs better than FS-RBFNN and ES-RBFNN, and our proposed method is feasible..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 312 (2019)
An all-optical implementation of Fredkin gate using Kerr effect
Dey Shuvra, De Paromita, and Mukhopadhyay Sourangshu
Quantum gates are the important breakthrough in current computation and high-end data processing. Several quantum logic gates have been implemented in last few decades. In this paper, the idea of all-optical (photonic) Fredkin gate is proposed, which performs the swapping operation by a control signal. Corresponding siQuantum gates are the important breakthrough in current computation and high-end data processing. Several quantum logic gates have been implemented in last few decades. In this paper, the idea of all-optical (photonic) Fredkin gate is proposed, which performs the swapping operation by a control signal. Corresponding simulation is also conducted with MATLAB, which shows the same result as the theoretical prediction..
Optoelectronics Letters
- Publication Date: May. 20, 2020
- Vol. 15, Issue 4, 317 (2019)
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