Journals >Frontiers of Optoelectronics
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2021
Volume: 14 Issue 4
17 Article(s)
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RESEARCH ARTICLE
Optical trapping using transverse electromagnetic (TEM)-like mode in a coaxial nanowaveguide
Yuanhao LOU, Xiongjie NING, Bei WU, and Yuanjie PANG
Optical traps have emerged as powerful tools for immobilizing and manipulating small particles in three dimensions. Fiber-based optical traps (FOTs) significantly simplify optical setup by creating trapping centers with single or multiple pieces of optical fibers. In addition, they inherit the flexibility and robustnesOptical traps have emerged as powerful tools for immobilizing and manipulating small particles in three dimensions. Fiber-based optical traps (FOTs) significantly simplify optical setup by creating trapping centers with single or multiple pieces of optical fibers. In addition, they inherit the flexibility and robustness of fiber-optic systems. However, trapping 10-nm-diameter nanoparticles (NPs) using FOTs remains challenging. In this study, we model a coaxial waveguide that works in the optical regime and supports a transverse electromagnetic (TEM)-like mode for NP trapping. Single NPs at waveguide front-end break the symmetry of TEM-like guided mode and lead to high transmission efficiency at far-field, thereby strongly altering light momentum and inducing a large-scale back-action on the particle. We demonstrate, via finitedifference time-domain (FDTD) simulations, that this FOT allows for trapping single 10-nm-diameter NPs at low power..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 399 (2021)
Design of hollow core step-index antiresonant fiber with stepped refractive indices cladding
Botao DENG, Chaotan SIMA, Hongyu TAN, Xiaohang ZHANG, Zhenggang LIAN, Guoqun CHEN, Qianqing YU, Jianghe XU, and Deming LIU
With the benefits of low latency, wide transmission bandwidth, and large mode field area, hollow-core antiresonant fiber (HC-ARF) has been a research hotspot in the past decade. In this paper, a hollow core step-index antiresonant fiber (HC-SARF), with stepped refractive indices cladding, is proposed and numerically deWith the benefits of low latency, wide transmission bandwidth, and large mode field area, hollow-core antiresonant fiber (HC-ARF) has been a research hotspot in the past decade. In this paper, a hollow core step-index antiresonant fiber (HC-SARF), with stepped refractive indices cladding, is proposed and numerically demonstrated with the benefits of loss reduction and bending improvement. Glass-based capillaries with both high (n = 1.45) and low (as low as n = 1.36) refractive indices layers are introduced and formatted in the cladding air holes. Using the finite element method to perform numerical analysis of the designed fiber, results show that at the laser wavelengths of 980 and 1064 nm, the confinement loss is favorably reduced by about 6 dB/km compared with the conventional uniform cladding HCARF. The bending loss, around 15 cm bending radius of this fiber, is also reduced by 2 dB/km. The cladding air hole radius in this fiber is further investigated to optimize the confinement loss and the mode field diameter with single-mode transmission behavior. This proposed HCSARF has great potential in optical fiber transmission and high energy delivery..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 407 (2021)
Toward coherent O-band data center interconnects
Pascal M. SEILER, Galina GEORGIEVA, Georg WINZER, Anna PECZEK, Karsten VOIGT, Stefan LISCHKE, Adel FATEMI, and Lars ZIMMERMANN
Upcoming generations of coherent intra/inter data center interconnects currently lack a clear path toward a reduction of cost and power consumption, which are the driving factors for these data links. In this work, the tradeoffs associated with a transition from coherent C-band to O-band silicon photonics are addressedUpcoming generations of coherent intra/inter data center interconnects currently lack a clear path toward a reduction of cost and power consumption, which are the driving factors for these data links. In this work, the tradeoffs associated with a transition from coherent C-band to O-band silicon photonics are addressed and evaluated. The discussion includes the fundamental components of coherent data links, namely the optical components, fiber link and transceivers. As a major component of these links, a monolithic silicon photonic BiCMOS O-band coherent receiver is evaluated for its potential performance and compared to an analogous C-band device..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 414 (2021)
Optical generation of UWB pulses utilizing Fano resonance modulation
Zhe XU, Yanyang ZHOU, Shuhuang CHEN, Liangjun LU, Gangqiang ZHOU, Jianping CHEN, and Linjie ZHOU
In this paper, we reported an integrated method to generate ultra-wideband (UWB) pulses of different orders based on a reconfigurable silicon micro-ring resonator-coupled Mach–Zehnder interferometer. Under proper operating conditions, the device can produce Fano resonances with a peak-to-valley extinction ratio of abovIn this paper, we reported an integrated method to generate ultra-wideband (UWB) pulses of different orders based on a reconfigurable silicon micro-ring resonator-coupled Mach–Zehnder interferometer. Under proper operating conditions, the device can produce Fano resonances with a peak-to-valley extinction ratio of above 20 dB. UWB monocycle and doublet signals with picosecond pulse widths are produced when the microring resonator is modulated by square and Gaussian electrical pulses, respectively. With our Fano resonance modulator on silicon photonics, it is promising to foresee versatile on-chip microwave signal generation..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 426 (2021)
Singular PT-symmetry broken point with infinite transmittance and reflectance-a classical analytical demonstration
Yingxin JIANG
To demonstrate the existence of singular parity-time symmetry (PT-symmetry) broken point in optics system, we designed a one-dimensional PT symmetric structure including N unit-cell with loss and gain materials in half. We performed an analytical deduction to obtain the transmittance and reflectance of the structure baTo demonstrate the existence of singular parity-time symmetry (PT-symmetry) broken point in optics system, we designed a one-dimensional PT symmetric structure including N unit-cell with loss and gain materials in half. We performed an analytical deduction to obtain the transmittance and reflectance of the structure basing on Maxwell’s equations. We found that with the exact structure unit-cell number and the imaginary part of refraction index, the transmittance and reflectance are both close to infinite. Such strict condition is called the singular point in this study. At the singular point position, both the transmission and reflection are direction-independent. Away from the singular point, the transmittance and reflectance become finite. In light of classical wave optics, the single unit and total structure both become the resonance units. The infinite transmittance and reflectance result from the resonance matching of single unit and total structure. In light of quantum theory, the singular point corresponds to the single eigenvalue of electromagnetic scattering matrix. The infinite transmittance and reflectance mean a huge energy transformation from pumping source to light waves. Numerical calculation and software simulation both demonstrate the result..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 438 (2021)
Interface phonon polariton coupling to enhance graphene absorption
Zhenyao CHEN, Junjie MEI, Ye ZHANG, Jishu TAN, Qing XIONG, and Changhong CHEN
Here we present a graphene photodetector of which the graphene and structural system infrared absorptions are enhanced by interface phonon polariton (IPhP) coupling. IPhPs are supported at the SiC/AlN interface of device structure and used to excite interband transitions of the intrinsic graphene under gated-field tuniHere we present a graphene photodetector of which the graphene and structural system infrared absorptions are enhanced by interface phonon polariton (IPhP) coupling. IPhPs are supported at the SiC/AlN interface of device structure and used to excite interband transitions of the intrinsic graphene under gated-field tuning. The simulation results show that at normal incidence the absorbance of graphene or system reaches up to 43% or closes to unity in a mid-infrared frequency range. In addition, we found the peak-absorption frequency is mainly decided by the AlN thickness, and it has a red-shift as the thickness decreases. This structure has great application potential in graphene infrared detection technology..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 445 (2021)
Oxide perovskite Ba2AgIO6 wafers for X-ray detection
Longbo YANG, Jincong PANG, Zhifang TAN, Qi XIAO, Tong JIN, Jiajun LUO, Guangda NIU, and Jiang TANG
X-ray detection is of great significance in biomedical, nondestructive, and scientific research. Lead halide perovskites have recently emerged as one of the most promising materials for direct X-ray detection. However, the lead toxicity remains a worrisome concern for further commercial application. Great efforts have X-ray detection is of great significance in biomedical, nondestructive, and scientific research. Lead halide perovskites have recently emerged as one of the most promising materials for direct X-ray detection. However, the lead toxicity remains a worrisome concern for further commercial application. Great efforts have been made to search for lead-free perovskites with similar optoelectronic properties. Here, we present a lead-free oxide double perovskite material Ba2AgIO6 for X-ray detection. The lead-free, all-inorganic nature, as well as the high density of Ba2AgIO6, promises excellent prospects in X-ray applications. By employing the hydrothermal method, we successfully synthesized highly crystalline Ba2AgIO6 powder with pure phase. Furthermore, we prepared Ba2AgIO6 wafers through isostatic pressure and built X-ray detectors with Au/Ba2AgIO6 wafer/Au photoconductive structure. The as-prepared X-ray detectors showed a sensitivity of 18.9 μC/(Gyair·cm2) at 5 V/mm, similar to commercial α-Se detectors showcasing their advantages for X-ray detection..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 473 (2021)
Rapid thermal evaporation for cadmium selenide thin-film solar cells
Kanghua LI, Xuetian LIN, Boxiang SONG, Rokas KONDROTAS, Chong WANG, Yue LU, Xuke YANG, Chao CHEN, and Jiang TANG
Cadmium selenide (CdSe) belongs to the binary II-VI group semiconductor with a direct bandgap of ~1.7 eV. The suitable bandgap, high stability, and low manufacturing cost make CdSe an extraordinary candidate as the top cell material in silicon-based tandem solar cells. However, only a few studies have focused on CdSe tCadmium selenide (CdSe) belongs to the binary II-VI group semiconductor with a direct bandgap of ~1.7 eV. The suitable bandgap, high stability, and low manufacturing cost make CdSe an extraordinary candidate as the top cell material in silicon-based tandem solar cells. However, only a few studies have focused on CdSe thinfilm solar cells in the past decades. With the advantages of a high deposition rate (~2 μm/min) and high uniformity, rapid thermal evaporation (RTE) was used to maximize the use efficiency of CdSe source material. A stable and pure hexagonal phase CdSe thin film with a large grain size was achieved. The CdSe film demonstrated a 1.72 eV bandgap, narrow photoluminescence peak, and fast photoresponse. With the optimal device structure and film thickness, we finally achieved a preliminary efficiency of 1.88% for CdSe thin-film solar cells, suggesting the applicability of CdSe thin-film solar cells..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 482 (2021)
Improved stability of blue TADF organic electroluminescentdiodes via OXD-7 based mixed host
Weiguang LI, Jie TANG, Yanqiong ZHENG, Junbiao PENG, Jianhua ZHANG, Bin WEI, and Xifeng LI
Thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) have been demonstrated in applications such as displays and solid-state lightings. However, weak stability and inefficient emission of blue TADF OLEDs are two key bottlenecks limiting the development of solution processable displays aThermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) have been demonstrated in applications such as displays and solid-state lightings. However, weak stability and inefficient emission of blue TADF OLEDs are two key bottlenecks limiting the development of solution processable displays and white light sources. This work presents a solution-processed OLED using a blue-emitting TADF small molecule bis[4-(9,9-dimethyl-9,10-dihydroacridine) phenyl]sulfone (DMAC-DPS) as an emitter. We comparatively investigated the effects of single host poly(Nvinylcarbazole) (PVK) and a co-host of 60% PVK and 30% 2,2′-(1,3-phenylene)-bis[5-(4-tert-butylphenyl)- 1,3,4-oxadiazole] (OXD-7) on the device performance (the last 10% is emitter DMAC-DPS). The co-host device shows lower turn-on voltage, similar maximum luminance, and much slower external quantum efficiency (EQE) rolloff. In other words, device stability improved by doping OXD-7 into PVK, and the device impedance simultaneously and significantly reduced from 8.6 103 to 4.2 103 W at 1000 Hz. Finally, the electroluminescent stability of the co-host device was significantly enhanced by adjusting the annealing temperature..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 491 (2021)
Light-emission organic solar cells with MoO3:Al interfacial layer–preparation and characterizations
Xinran LI, Yanhui LOU, and Zhaokui WANG
A light-emitting organic solar cell (LE-OSC) with electroluminescence (EL) and photovoltaic (PV) properties is successfully fabricated by connecting the EL and PV units using a MoO3:Al co-evaporation interfacial layer, which has suitable work function and good transmittance. PV and EL units are fabricated based on polyA light-emitting organic solar cell (LE-OSC) with electroluminescence (EL) and photovoltaic (PV) properties is successfully fabricated by connecting the EL and PV units using a MoO3:Al co-evaporation interfacial layer, which has suitable work function and good transmittance. PV and EL units are fabricated based on poly(3-hexylthiophene) (P3HT)-indene-C60 bisadduct (IC60BA) blends, and 4,4′-bis (N-carbazolyl) biphenyl-factris (2-phenylpyridine) iridium (Ir(ppy)3), respectively. The work function and the transmittance of the MoO3:Al co-evaporation are measured and adjusted by the ultraviolet photoelectron spectroscopy and the optical spectrophotometer to obtain the better bi-functional device performance. The forward- and reverse-biased current density-voltage characteristics in dark and under illumination are evaluated to better understand the operational mechanism of the LE-OSCs. A maximum luminance of 1550 cd/m2 under forward bias and a power conversion efficiency of 0.24% under illumination (100 mW/cm2) are achieved in optimized LE-OSCs. The proposed device structure is expected to provide valuable information in the film conditions for understanding the polymer blends internal conditions and meliorating the film qualities..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 499 (2021)
Growth of InGaN-based blue-LED on AlN/sapphire sputtered with different oxygen flow rate
Jiahui HU, Feng WU, Jiangnan DAI, and Changqing CHEN
Indium gallium nitride (InGaN) based blue light-emitting diodes (LEDs) suffer from insufficient crystal quality and serious efficiency droop in large forward current. In this paper, the InGaN-based blue LEDs are grown on sputtered aluminum nitride (AlN) films to improve the device light power and weaken the efficiency Indium gallium nitride (InGaN) based blue light-emitting diodes (LEDs) suffer from insufficient crystal quality and serious efficiency droop in large forward current. In this paper, the InGaN-based blue LEDs are grown on sputtered aluminum nitride (AlN) films to improve the device light power and weaken the efficiency droop. The effects of oxygen flow rate on the sputtering of AlN films on sapphire and device performance of blue LEDs are studied in detail. The mechanism of external quantum efficiency improvement is related to the change of V-pits density in multiple quantum wells. The external quantum efficiency of 66% and 3-Voperating voltage are measured at a 40-mA forward current of with the optimal oxygen flow rate of 4 SCCM..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 507 (2021)
A QoT prediction technique based on machine learning and NLSE for QoS and new lightpaths in optical communication networks
Yongfeng FU, Jing CHEN, Weiming WU, Yu HUANG, Jie HONG, Long CHEN, and Zhongbin LI
In this paper, we proposed a quality of transmission (QoT) prediction technique for the quality of service (QoS) link setup based on machine learning classifiers, with synthetic data generated using the transmission equations instead of the Gaussian noise (GN) model. The proposed technique uses some link and signal chaIn this paper, we proposed a quality of transmission (QoT) prediction technique for the quality of service (QoS) link setup based on machine learning classifiers, with synthetic data generated using the transmission equations instead of the Gaussian noise (GN) model. The proposed technique uses some link and signal characteristics as input features. The bit error rate (BER) of the signals was compared with the forward error correction threshold BER, and the comparison results were employed as labels. The transmission equations approach is a better alternative to the GN model (or other similar margin-based models) in the absence of real data (i.e., at the deployment stage of a network) or the case that real data are scarce (i.e., for enriching the dataset/reducing probing lightpaths); furthermore, the three classifiers trained using the data of the transmission equations are more reliable and practical than those trained using the data of the GN model. Meanwhile, we noted that the priority of the three classifiers should be support vector machine (SVM)>K nearest neighbor (KNN)>logistic regression (LR) as shown in the results obtained by the transmission equations, instead of SVM>LR>KNN as in the results of the GN model..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 513 (2021)
Drilling high aspect ratio holes by femtosecond laser filament with aberrations
Manshi WANG, Zhiqiang YU, Nan ZHANG, and Weiwei LIU
A near-infrared femtosecond laser is focused by a 100 mm-focal-length plano-convex lens to form a laser filament, which is employed to drill holes on copper targets. By shifting or rotating the focusing lens, additional aberration is imposed on the focused laser beam, and significant influence is produced on the aspectA near-infrared femtosecond laser is focused by a 100 mm-focal-length plano-convex lens to form a laser filament, which is employed to drill holes on copper targets. By shifting or rotating the focusing lens, additional aberration is imposed on the focused laser beam, and significant influence is produced on the aspect ratio and cross-sectional shape of the micro-holes. Experimental results show that when proper aberration is introduced, the copper plate with a thickness of 3 mm can be drilled through with an aspect ratio of 30, while no through-holes can be drilled on 3-mm-thickness copper plates by femtosecond laser with minimized aberration. In addition, when femtosecond laser filament with large astigmatism is used, micro-holes that had a length to width ratio up to 3.3 on the cross-section are obtained. Therefore, the method proposed here can be used to fabricate long oval holes with high aspect ratios..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 522 (2021)
Improved phase retrieval in holographic data storage based on a designed iterative embedded data
Changyu YU, Suping WANG, Ruixian CHEN, Jianying HAO, Qijing ZHENG, Jinyu WANG, Xianying QIU, Kun WANG, Dakui LIN, Yi YANG, Hui LI, Xiao LIN, and Xiaodi TAN
Embedded data are used to retrieve phases quicker with high accuracy in phase-modulated holographic data storage (HDS). We propose a method to design an embedded data distribution using iterations to enhance the intensity of the high-frequency signal in the Fourier spectrum. The proposed method increases the antinoise Embedded data are used to retrieve phases quicker with high accuracy in phase-modulated holographic data storage (HDS). We propose a method to design an embedded data distribution using iterations to enhance the intensity of the high-frequency signal in the Fourier spectrum. The proposed method increases the antinoise performance and signal-to-noise ratio (SNR) of the Fourier spectrum distribution, realizing a more efficient phase retrieval. Experiments indicate that the bit error rate (BER) of this method can be reduced by a factor of one after 10 iterations..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 529 (2021)
REVIEW ARTICLE
Recent progress of semiconductor optoelectronic fibers
Hei Chit Leo TSUI, and Noel HEALY
Semiconductor optoelectronic fiber technology has seen rapid development in recent years thanks to advancements in fabrication and post-processing techniques. Integrating the optical and electronic functionality of semiconductor materials into a fiber geometry has opened up many possibilities, such as in-fiber frequencSemiconductor optoelectronic fiber technology has seen rapid development in recent years thanks to advancements in fabrication and post-processing techniques. Integrating the optical and electronic functionality of semiconductor materials into a fiber geometry has opened up many possibilities, such as in-fiber frequency generation, signal modulation, photodetection, and solar energy harvesting. This review provides an overview of the stateof- the-art in semiconductor optoelectronic fibers, including fabrication and post-processing methods, materials and their optical properties. The applications in nonlinear optics, optical-electrical conversion, lasers and multimaterial functional fibers will also be highlighted..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 383 (2021)
Recent progress in the research on using CuSbS2 and its derivative CuPbSbS3 as absorbers in case of photovoltaic devices
Muyi ZHANG, Chong WANG, Chao CHEN, and Jiang TANG
Thin-film solar cells show considerable application potential as alternative photovoltaic technologies. Cuprous antimony chalcogen materials and their derivatives, represented as CuSbS2 and CuPbSbS3, respectively, exhibit the advantages of low cost, massive elemental abundance, stability, and good photoelectric propertThin-film solar cells show considerable application potential as alternative photovoltaic technologies. Cuprous antimony chalcogen materials and their derivatives, represented as CuSbS2 and CuPbSbS3, respectively, exhibit the advantages of low cost, massive elemental abundance, stability, and good photoelectric properties, including a suitable bandgap and large optical absorption coefficient. These advantages demonstrate that they can be used as light absorbers in photovoltaic applications. In this study, we review the major properties, fabrication methods, and recent progress of the performance of the devices containing CuSbS2 and CuPbSbS3. Furthermore, the limitations and future development prospects with respect to the CuSbS2 and CuPbSbS3 solar cells are discussed..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 450 (2021)
Self-trapped exciton emission in inorganic copper(I) metal halides
Boyu ZHANG, Xian WU, Shuxing ZHOU, Guijie LIANG, and Qingsong HU
The broad emission and high photoluminescence quantum yield of self-trapped exciton (STE) radiative recombination emitters make them an ideal solution for single-substrate, white, solid-state lighting sources. Unlike impurities and defects in semiconductors, the formation of STEs requires a lattice distortion, along wiThe broad emission and high photoluminescence quantum yield of self-trapped exciton (STE) radiative recombination emitters make them an ideal solution for single-substrate, white, solid-state lighting sources. Unlike impurities and defects in semiconductors, the formation of STEs requires a lattice distortion, along with strong electron–phonon coupling, in low electrondimensional materials. The photoluminescence of inorganic copper(I) metal halides with low electron-dimensionality has been found to be the result of STEs. These materials were of significant interest because of their leadfree, all-inorganic structures, and high luminous efficiencies. In this paper, we summarize the luminescence characteristics of zero- and one-dimensional inorganic copper(I) metal halides with STEs to provide an overview of future research opportunities..
Frontiers of Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 14, Issue 4, 459 (2021)
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