Journals >Optoelectronics Letters
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2020
Volume: 16 Issue 6
16 Article(s)
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Synthesis and opto-electrical properties of Cu2NiSnS4 nanoparticles using a facile solid-phase process at low temperature
Shi-na LI, Rui-xin MA, and Jian-wen NIU
Cu2NiSnS4 nanoparticles were prepared for the first time using a facile solid-phase process at a temperature of 180 °C. The crystalline structure, morphology and optical properties of the Cu2NiSnS4 nanoparticles were characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FECu2NiSnS4 nanoparticles were prepared for the first time using a facile solid-phase process at a temperature of 180 °C. The crystalline structure, morphology and optical properties of the Cu2NiSnS4 nanoparticles were characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM) and ultraviolet-visible (UV-vis) spectrophotometer. The band gap and conversion efficiency of Cu2NiSnS4 nanoparticles were studied at various temperature. The results showed that the Cu2NiSnS4 nanoparticles exhibited an optimum band gap of 1.58 eV and a conversion efficiency of 0.64% at 180 °C, indicating that it maybe be useful in low-cost thin film solar cells..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 401 (2020)
Tunable frequency-multiplying optoelectronic oscillator based on a dual-parallel Mach-Zehnder modulator incorporating a phase-shifted fiber Bragg grating
Yao ZHANG, Ti-gang NING, Jing LI, Jing-jing ZHENG, Ling LIU, Xiao-wei DONG, and Li PEI
A tunable frequency-multiplying optoelectronic oscillator (OEO) based on a dual-parallel Mach-Zehnder modulator (DPMZM) is proposed and experimentally demonstrated. In the proposed system, the tunable fundamental microware signal is generated by a tunable optoelectronic oscillator incorporating a phase-shifted fiber BrA tunable frequency-multiplying optoelectronic oscillator (OEO) based on a dual-parallel Mach-Zehnder modulator (DPMZM) is proposed and experimentally demonstrated. In the proposed system, the tunable fundamental microware signal is generated by a tunable optoelectronic oscillator incorporating a phase-shifted fiber Bragg grating (PS-FBG). By adjusting the DC bias of the DPMZM, the frequency-doubled microwave signal with a tunable frequency range from 11 GHz to 20 GHz and the frequency-quadrupled microwave signal with a tunable frequency range from 22.5 GHz to 26 GHz are generated. The phase noises of the fundamental, frequency-doubled and frequency- quadrupled signals at 10 kHz offset frequency are -105.9 dBc/Hz, -103.3 dBc/Hz and -86.2 dBc/Hz, respectively..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 405 (2020)
A life-prediction method for lithium-ion batteries based on a fusion model and an attention mechanism
Xian-bao WANG, Fei-teng WU, and Ming-hai YAO
The current life-prediction models for lithium-ion batteries have several problems, such as the construction of complex feature structures, a high number of feature dimensions, and inaccurate prediction results. To overcome these problems, this paper proposes a deep-learning model combining an autoencoder network and aThe current life-prediction models for lithium-ion batteries have several problems, such as the construction of complex feature structures, a high number of feature dimensions, and inaccurate prediction results. To overcome these problems, this paper proposes a deep-learning model combining an autoencoder network and a long short-term memory network. First, this model applies the characteristics of the autoencoder to reduce the dimensionality of the high-dimensional features extracted from the battery data set and realize the fusion of complex time-domain features, which overcomes the problems of redundant model information and low computational efficiency. This model then uses a long short-term memory network that is sensitive to time-series data to solve the long-path dependence problem in the prediction of battery life. Lastly, the attention mechanism is used to give greater weight to features that have a greater impact on the target value, which enhances the learning effect of the model on the long input sequence. To verify the efficacy of the proposed model, this paper uses NASA's lithium-ion battery cycle life data set..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 410 (2020)
A robust salinity sensor based on encapsulated longperiod grating in microfiber
Shu-hui WU, Wa JIN, Wei-hong BI, Xia LI, Lin-ke ZHANG, and Yun JIN
A robust fiber sensor for salinity measurement based on encapsulated long-period grating in microfiber is proposed. The long-period grating is fabricated in microfiber by inducing periodical deformation with CO2 laser, which is then encapsulated in a holey capillary tube. The encapsulation tube is designed to effectiveA robust fiber sensor for salinity measurement based on encapsulated long-period grating in microfiber is proposed. The long-period grating is fabricated in microfiber by inducing periodical deformation with CO2 laser, which is then encapsulated in a holey capillary tube. The encapsulation tube is designed to effectively protect the microfiber from external interference, but does not change the optical properties of the fiber and the response speed of the sensor, which makes the sensor more robust for real applications. Experimental results show that the sensor can achieve a sensitivity of 2.16 nm/% with a good linearity for concentration from 0% to 20%. It is theoretically proved that the sensitivity can be further improved by optimizing the diameter parameters. Such structure may be used as low loss evanescent-wave-coupled optical absorption, fluorescent and gain cells, photoacoustic cells, and etc..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 418 (2020)
Co-doping method used to improve the charge transport balance in solution processed OLEDs
Jun-tao HU, Peng WANG, Xue XIAO, Sheng HU, Kai XU, and Xiang-hua WANG
In this paper, co-doping method is used to improve the current efficiency of solution-processed organic light-emitting diodes (OLEDs). By changing the ratio of two thermally activated delayed fluorescent (TADF) emitters, we studied the performance of device and its mechanism. A solution processed OLED with a structure In this paper, co-doping method is used to improve the current efficiency of solution-processed organic light-emitting diodes (OLEDs). By changing the ratio of two thermally activated delayed fluorescent (TADF) emitters, we studied the performance of device and its mechanism. A solution processed OLED with a structure of indium tin oxide (ITO, 150 nm)/PEDOT:PSS (30 nm)/CBP:4CzIPN-x%:4CzPN-y% (30 nm)/TPBi (40 nm)/LiF (1 nm)/Al (100 nm) was fabricated. The current efficiencies of 26.6 cd/A and 26.4 cd/A were achieved by the devices with dopant ratio of 6% 4CzIPN:2% 4CzPN and 2% 4CzIPN:6% 4CzPN in emitting material layer (EML), respectively. By investigating the tendency of current density change in devices with different doping ratio, we suggested that the enhancement of the current efficiency should be due to the charge transport balance improvement induced by assist dopant in EML..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 423 (2020)
Humidity and temperature sensor based on GOQDs-PVA coated tapered no-core fiber combined with FBG
Qi-hang CHENG, Ai-ling ZHANG, Hong-gang PAN, Wen LI, and Ce SUN
A simple structure optical fiber sensor for relative humidity (RH) and temperature measurement is proposed and verified in this paper, which is based on graphene oxide quantum dots and polyvinyl alcohol (GOQDs-PVA) composite coated tapered no-core fiber (NCF) combined with a fiber Bragg grating (FBG). FBG is insensitivA simple structure optical fiber sensor for relative humidity (RH) and temperature measurement is proposed and verified in this paper, which is based on graphene oxide quantum dots and polyvinyl alcohol (GOQDs-PVA) composite coated tapered no-core fiber (NCF) combined with a fiber Bragg grating (FBG). FBG is insensitive to humidity and sensitive to temperature, which is used to compensate temperature of the sensor. Experimental results show this sensor has humidity sensitivity of 143.27 pm/%RH ranging from 30%RH to 80%RH and the temperature sensitivity of 9.21 pm/℃ The proposed sensor has advantages of simple structure, good repeatability, and good stability, which is expected to be used in both RH and temperature measurement in biological and chemical fields..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 428 (2020)
Compact external cavity diode laser for quantum experiments
Chun-hua WEI, Cheng-lin ZUO, Lei LIANG, and Shu-hua YAN
We present a compact and practical scheme of building a ~780 nm external cavity diode laser (ECDL) whose wavelength is mainly determined by an interference filter. The Lorentzian linewidth measured by the heterodyne beating between two identical lasers is 60 kHz, and the geometry size of the laser is only 71.5 mm×We present a compact and practical scheme of building a ~780 nm external cavity diode laser (ECDL) whose wavelength is mainly determined by an interference filter. The Lorentzian linewidth measured by the heterodyne beating between two identical lasers is 60 kHz, and the geometry size of the laser is only 71.5 mm×65 mm×40 mm. The linear cavity design is less sensitive to misalignment induced by mechanical and thermal disturbances, and in comparison to a common grating-based design, the sensitivity to vibration is substantially reduced. Due to its excellent performance, the laser design has already been applied to cold atom trapping experiments. This interference filter ECDL method can also be extended to other wavelengths and widen the application range of diode laser..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 433 (2020)
Design of multi-channel terahertz beam splitter based on Z-shaped metasurface
Pan Wu, Wang Xue-yin, Chen Qi, Ren Xin-yu, and Ma Yong
A reflective beam splitter is proposed and verified. The unit cell of the beam splitter is composed of a metal pattern, a dielectric substrate, and a metallic ground. Each subarray structure of the device is composed of four unit cells, which are gradually rotated at 45°. The horizontal and vertical subarrays formA reflective beam splitter is proposed and verified. The unit cell of the beam splitter is composed of a metal pattern, a dielectric substrate, and a metallic ground. Each subarray structure of the device is composed of four unit cells, which are gradually rotated at 45°. The horizontal and vertical subarrays form a 4×4 gradient metasurface supercell. In the operating frequency band, the incident linearly polarized terahertz wave is reflected and divided into four beams of approximately equal power but different propagation directions. The proposed terahertz beam splitter based on metasurface has the advantages of small size, low cost and easy processing, and can be applied to terahertz stealth and imaging..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 437 (2020)
Low phase noise and quasi-tunable millimeter-wave generator using a passively InAs/InP mode-locked quantum dot laser
Li LIU, Yang-guang LIU, Xiao-min ZHANG, Bang-quan LIU, and Xiu-pu ZHANG
A low phase noise millimeter-wave (MMW) signal generator is proposed and experimentally demonstrated with a C-band passively Fabry-Pérot (F-P) quantum dot mode-locked laser. A novel method is proposed to generate low phase noise MMW signal, which is simply based on a commercial off-the-shelf dual-driven LiNbO3 MacA low phase noise millimeter-wave (MMW) signal generator is proposed and experimentally demonstrated with a C-band passively Fabry-Pérot (F-P) quantum dot mode-locked laser. A novel method is proposed to generate low phase noise MMW signal, which is simply based on a commercial off-the-shelf dual-driven LiNbO3 Mach-Zehnder modulator and a passively F-P quantum dot mode-locked laser. MMW signal with the frequency of 30 GHz, 45 GHz and 90 GHz respectively is obtained experimentally. Single-sideband phase noise of the 30 GHz and 45 GHz MMW signal is -112 dBc/Hz and -106 dBc/Hz at an offset of 1 kHz, respectively. The linewidth of the 30 GHz and 45 GHz MMW signal is about from 225 Hz and 239 Hz. This is considered a very simple MMW generator with a quasi-tunable broadband and ultra-low phase noise..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 441 (2020)
Study on photocatalytic activity of MoS2/ZnO composite in visible light
Chun-mei TANG, Hong-yan ZHANG, and Jun ZHANG
A series of MoS2/ZnO compound photocatalysts with different mass ratios were successfully prepared by hydrothermal method. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and UV-vis absorption were used to characterize the prepared MoS2/ZnO photocatalysts. It was A series of MoS2/ZnO compound photocatalysts with different mass ratios were successfully prepared by hydrothermal method. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and UV-vis absorption were used to characterize the prepared MoS2/ZnO photocatalysts. It was proved that the combination of MoS2 and ZnO can increase the content of oxygen vacancies on surface of ZnO, thus improving the light absorption capacity in visible light region and reducing the band gap of ZnO. And the photocatalytic performance of ZnO was improved. Experimental results show that the MoS2/ZnO (3 wt%) compound has the highest degradation rate for methylene blue (MB) under visible light, which means that it has the best photocatalytic activity among all the prepared samples..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 446 (2020)
Sn doped ZnO thin films as high resistivity window layer for Cu(In,Ga)Se2 solar cells
Bo-yan LI, Fang-fang LIU, and Lie LIN
For high efficiency Cu(In,Ga)Se2 (CIGS) solar cell, the high-resistivity layer with high optical transmittance has to be adopted between the buffer layer and the high-conductivity window layer. In this paper, we propose Sn doped ZnO (ZTO) film, instead of the traditional intrinsic ZnO (i-ZnO) film, as an alternative n-For high efficiency Cu(In,Ga)Se2 (CIGS) solar cell, the high-resistivity layer with high optical transmittance has to be adopted between the buffer layer and the high-conductivity window layer. In this paper, we propose Sn doped ZnO (ZTO) film, instead of the traditional intrinsic ZnO (i-ZnO) film, as an alternative n-type high-resistivity window layer for CIGS solar cell. In this experiment, both ZTO and i-ZnO films are strong (002) oriented, and the surface morphologies of the two films are almost the same. The statistical roughnesses of i-ZnO film and ZTO film are 0.58 nm and 0.63 nm, respectively. However, the optical transmittance of ZTO film is higher than that of i-ZnO film with the same thickness. The efficiency of ZTO based CIGS cell was 14.24%, which is almost the same as the efficiency of i-ZnO based CIGS cell. These results fully suggest that it is very feasible to replace i-ZnO with ZTO as the high resistant window layer..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 451 (2020)
Dynamic multicast sharing protection algorithm based on fuzzy game in multi-domain optical network
Qi-wu WU, Hao CHEN, Ling-zhi JIANG, and Yang ZHOU
Aiming at the problem of dynamic multicast service protection in multi-domain optical network, this paper proposes a dynamic multicast sharing protection algorithm based on fuzzy game in multi-domain optical network. The algorithm uses the minimum cost spanning tree strategy and fuzzy game theory. First, it virtualizesAiming at the problem of dynamic multicast service protection in multi-domain optical network, this paper proposes a dynamic multicast sharing protection algorithm based on fuzzy game in multi-domain optical network. The algorithm uses the minimum cost spanning tree strategy and fuzzy game theory. First, it virtualizes two planes to calculate the multicast tree and the multicast protection tree respectively. Then, it performs a fuzzy game to form a cooperative alliance to optimize the path composition of each multicast tree. Finally, it generates a pair of optimal multicast work tree and multicast protection tree for dynamic multicast services. The time complexity of the algorithm is O(k3m2n), where n represents the number of nodes in the networks, k represents the number of dynamic multicast requests, and m represents the number of destination nodes for each multicast request. The experimental results show that the proposed algorithm reduces significantly the blocking rate of dynamic multicast services, and improves the utilization of optical network resources within a certain number of dynamic multicast request ranges..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 455 (2020)
Research on separation and enhancement of speech micro-vibration from macro motion
Hong-kai CHEN, Ting-feng WANG, Shi-song WU, and Yuan-yang LI
Based on the 1 550 nm all-fiber pulsed laser Doppler vibrometer (LDV) system independently developed by our laboratory, empirical mode decomposition (EMD) and optimally modified Log-spectral amplitude estimator (OM-LSA) algorithms are associated to separate the speech micro-vibration from the target macro motion. This Based on the 1 550 nm all-fiber pulsed laser Doppler vibrometer (LDV) system independently developed by our laboratory, empirical mode decomposition (EMD) and optimally modified Log-spectral amplitude estimator (OM-LSA) algorithms are associated to separate the speech micro-vibration from the target macro motion. This combined algorithm compensates for the weakness of the EMD algorithm in denoising and the inability of the OM-LSA algorithm on signal separation, achieving separation and simultaneous acquisition of the macro motion and speech micro-vibration of a target. The experimental results indicate that using this combined algorithm, the LDV system can functionally operate within 30 m and gain a 4.21 dB promotion in the signal-to-noise ratio (SNR) relative to a traditional OM-LSA algorithm..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 462 (2020)
Real-time human blood pressure measurement based on laser self-mixing interferometry with extreme learning machine
Xiu-lin WANG, Li-ping Lü, Lu HU, and Wen-cai HUANG
In this paper, we present a method based on self-mixing interferometry combing extreme learning machine for real-time human blood pressure measurement. A signal processing method based on wavelet transform is applied to extract reversion point in the self-mixing interference signal, thus the pulse wave profile is succeIn this paper, we present a method based on self-mixing interferometry combing extreme learning machine for real-time human blood pressure measurement. A signal processing method based on wavelet transform is applied to extract reversion point in the self-mixing interference signal, thus the pulse wave profile is successfully reconstructed. Considering the blood pressure values are intrinsically related to characteristic parameters of the pulse wave, 80 samples from the MIMIC-II database are used to train the extreme learning machine blood pressure model. In the experiment, 15 measured samples of pulse wave signal are used as the prediction sets. The results show that the errors of systolic and diastolic blood pressure are both within 5 mmHg compared with that by the Coriolis method..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 467 (2020)
Femtosecond laser processing stainless steel foil and its Fourier spectrum detection
Dong-ming TU, Hao-yue MA, Xiao-rui JIANG, Hong-liang LIU, Peng-fei WU, Li-wei SONG, and Ming-wei WANG
In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and "thermal processing" and their mutual conversion, and determine the "cold processing"In this paper, we use femtosecond laser pulse to scribe 304 stainless steel foil, detect the Fourier transform infrared spectrum of the sample before and after processing, confirm the "cold processing" and "thermal processing" and their mutual conversion, and determine the "cold processing" parameter window. The ablation threshold and incubation coefficient of 304 stainless steel foil are calculated, and the effects of scanning speed and effective pulse number on the ablation threshold are analyzed. The ANSYS software is used to simulate the radial and axial temperature distributions of the surface on 304 stainless steel foil sample and the heat-affected zone with a femtosecond laser fluence of 10 J/cm2 and an effective number of pulses of 1 200 are obtained. In the aspect of spectral detection, the Fourier transform infrared spectra of the sample before and after processing are measured and two processing mechanisms of "cold processing" and "hot processing" are confirmed, which proves that we can achieve the conversion between "cold processing" and "hot processing" by changing the laser fluence and determine the "cold processing" laser fluence range..
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 471 (2020)
Investigation of response time of small footprint photonic crystal AND logic gate
Mohebzadeh-Bahabady1 Ahmad, and Olyaee Saeed
In this paper, the response time of all-optical AND logic gate using the triangular photonic crystal lattice is investigated. The proposed logic gate consists of a photonic crystal nano-resonator formed by changing the size of the dielectric rods. The structure benefits the interference effect mechanism. The contrast rIn this paper, the response time of all-optical AND logic gate using the triangular photonic crystal lattice is investigated. The proposed logic gate consists of a photonic crystal nano-resonator formed by changing the size of the dielectric rods. The structure benefits the interference effect mechanism. The contrast ratio of the photonic crystal AND logic gate is obtained as 6 dB. In addition to simplicity, the designed nano-resonator increases the bit rate of logic gate. The delay time and footprint of logic gate are respectively 0.32 ps and 146 μm2. The proposed photonic crystal AND logic gate can operate at a bit rate of 3.12 Tbit/s.
Optoelectronics Letters
- Publication Date: Jan. 01, 1900
- Vol. 16, Issue 6, 477 (2020)
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