Frontiers of Optoelectronics

ISSN 2095-2759 (Print)
ISSN 2095-2767 (Online)
CN 10-1029/TN
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Formerly Known as Frontiers of Optoelectronics in China

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 Select Universal numerical calculation method for the Berry curvature and Chern numbers of typical topological photonic crystals Chenyang WANG, Hongyu ZHANG, Hongyi YUAN, Jinrui ZHONG, Cuicui LU Front. Optoelectron..  2020, 13 (1): 73-88.   https://doi.org/10.1007/s12200-019-0963-9 Abstract   HTML   PDF (4609KB) Chern number is one of the most important criteria by which the existence of a topological photonic state among various photonic crystals can be judged; however, few reports have presented a universal numerical calculation method to directly calculate the Chern numbers of different topological photonic crystals and have denoted the influence of different structural parameters. Herein, we demonstrate a direct and universal method based on the finite element method to calculate the Chern number of the typical topological photonic crystals by dividing the Brillouin zone into small zones, establishing new properties to obtain the discrete Chern number, and simultaneously drawing the Berry curvature of the first Brillouin zone. We also explore the manner in which the topological properties are influenced by the different structure types, air duty ratios, and rotating operations of the unit cells; meanwhile, we obtain large Chern numbers from −2 to 4. Furthermore, we can tune the topological phase change via different rotation operations of triangular dielectric pillars. This study provides a highly efficient and simple method for calculating the Chern numbers and plays a major role in the prediction of novel topological photonic states. Cited: Crossref(1)
 Select A review of multiple optical vortices generation: methods and applications Long ZHU, Jian WANG Front. Optoelectron..  2019, 12 (1): 52-68.   https://doi.org/10.1007/s12200-019-0910-9 Abstract   HTML   PDF (6799KB) Optical vortices carrying orbital angular momentum (OAM) have attracted increasing interest in recent years. Optical vortices have seen a variety of emerging applications in optical manipulation, optical trapping, optical tweezers, optical vortex knots, imaging, microscopy, sensing, metrology, quantum information processing, and optical communications. In various optical vortices enabled applications, the generation of multiple optical vortices is of great importance. In this review article, we focus on the methods of multiple optical vortices generation and its applications. We review the methods for generating multiple optical vortices in three cases, i.e., 1-to-N collinear OAM modes, 1-to-N OAM mode array and N-to-N collinear OAM modes. Diverse applications of multiple OAM modes in optical communications and non-communication areas are presented. Future trends, perspectives and opportunities are also discussed. Cited: Crossref(10)
 Select Topological photonic crystals: a review Hongfei WANG, Samit Kumar GUPTA, Biye XIE, Minghui LU Front. Optoelectron..  2020, 13 (1): 50-72.   https://doi.org/10.1007/s12200-019-0949-7 Abstract   HTML   PDF (5403KB) The field of topological photonic crystals has attracted growing interest since the inception of optical analog of quantum Hall effect proposed in 2008. Photonic band structures embraced topological phases of matter, have spawned a novel platform for studying topological phase transitions and designing topological optical devices. Here, we present a brief review of topological photonic crystals based on different material platforms, including all-dielectric systems, metallic materials, optical resonators, coupled waveguide systems, and other platforms. Furthermore, this review summarizes recent progress on topological photonic crystals, such as higher-order topological photonic crystals, non-Hermitian photonic crystals, and nonlinear photonic crystals. These studies indicate that topological photonic crystals as versatile platforms have enormous potential applications in maneuvering the flow of light. Cited: Crossref(2)
 Select Antimony doped Cs2SnCl6 with bright and stable emission Jinghui LI, Zhifang TAN, Manchen HU, Chao CHEN, Jiajun LUO, Shunran LI, Liang GAO, Zewen XIAO, Guangda NIU, Jiang TANG Front. Optoelectron..  2019, 12 (4): 352-364.   https://doi.org/10.1007/s12200-019-0907-4 Abstract   HTML   PDF (3339KB) Lead halide perovskites, with high photoluminescence efficiency and narrow-band emission, are promising materials for display and lighting. However, the lead toxicity and environmental sensitivity hinder their potential applications. Herein, a new antimony-doped lead-free inorganic perovskites variant Cs2SnCl6:xSb is designed and synthesized. The perovskite variant Cs2SnCl6:xSb exhibits a broadband orange-red emission, with a photoluminescence quantum yield (PLQY) of 37%. The photoluminescence of Cs2SnCl6:xSb is caused by the ionoluminescence of Sb3+ within Cs2SnCl6 matrix, which is verified by temperature dependent photoluminescence (PL) and PL decay measurements. In addition, the all inorganic structure renders Cs2SnCl6:xSb with excellent thermal and water stability. Finally, a white light-emitting diode (white-LED) is fabricated by assembling Cs2SnCl6:0.59%Sb, Cs2SnCl6:2.75%Bi and Ba2Sr2SiO4:Eu2+ onto the commercial UV LED chips, and the color rendering index (CRI) reaches 81. Cited: Crossref(12)
 Select 2D materials as a new platform for photonic applications Jianji DONG, Zhipei SUN Front. Optoelectron..  2020, 13 (2): 89-90.   https://doi.org/10.1007/s12200-020-1059-2 Abstract   HTML   PDF (104KB)
 Select Review of fabrication methods of large-area transparent graphene electrodes for industry Petri MUSTONEN, David M. A. MACKENZIE, Harri LIPSANEN Front. Optoelectron..  2020, 13 (2): 91-113.   https://doi.org/10.1007/s12200-020-1011-5 Abstract   HTML   PDF (837KB) Graphene is a two-dimensional material showing excellent properties for utilization in transparent electrodes; it has low sheet resistance, high optical transmission and is flexible. Whereas the most common transparent electrode material, tin-doped indium-oxide (ITO) is brittle, less transparent and expensive, which limit its compatibility in flexible electronics as well as in low-cost devices. Here we review two large-area fabrication methods for graphene based transparent electrodes for industry: liquid exfoliation and low-pressure chemical vapor deposition (CVD). We discuss the basic methodologies behind the technologies with an emphasis on optical and electrical properties of recent results. State-of-the-art methods for liquid exfoliation have as a figure of merit an electrical and optical conductivity ratio of $43.5$, slightly over the minimum required for industry of $35$, while CVD reaches as high as $419$. Cited: Crossref(1)
 Select The smallest nanowire spectrometers Jianji DONG Front. Optoelectron..  2019, 12 (4): 341-341.   https://doi.org/10.1007/s12200-019-0983-5 Abstract   HTML   PDF (61KB)
 Select Screen printing process control for coating high throughput titanium dioxide films toward printable mesoscopic perovskite solar cells Zhining WAN, Mi XU, Zhengyang FU, Da LI, Anyi MEI, Yue HU, Yaoguang RONG, Hongwei HAN Front. Optoelectron..  2019, 12 (4): 344-351.   https://doi.org/10.1007/s12200-019-0904-7 Abstract   HTML   PDF (1059KB) Screen printing technique has been widely applied for the manufacturing of both traditional silicon solar cells and emerging photovoltaics such as dye-sensitized solar cells (DSSCs) and perovskite solar cells (PSCs). Particularly, we have developed a printable mesoscopic PSC based on a triple layer scaffold of TiO2/ZrO2/carbon. The deposition of the scaffold is entirely based on screen printing process, which provides a promising prospect for low-cost photovoltaics. However, the optimal thickness of the TiO2 layer for fabricating efficient printable PSCs is much smaller than the typical thickness of screen printed films. Here, we tune the concentration of the pastes and the printing parameters for coating TiO2 films, and successfully print TiO2 films with the thickness of 500−550 nm. The correlation between the thickness of the films and printing parameters such as the solid content and viscosity of the pastes, the printing speed and pressure, and the temperature has been investigated. Besides, the edge effect that the edge of the TiO2 films possesses a much larger thickness and printing positional accuracy have been studied. This work will significantly benefit the further development of printable mesoscopic PSCs. Cited: Crossref(4)
 Select Detection of photonic orbital angular momentum with micro- and nano-optical structures Chenhao WAN, Guanghao RUI, Jian CHEN, Qiwen ZHAN Front. Optoelectron..  2019, 12 (1): 88-96.   https://doi.org/10.1007/s12200-017-0730-8 Abstract   HTML   PDF (2237KB) Light with an optical orbital angular momentum (OAM) has attracted an increasing amount of interest and has found its way into many disciplines ranging from optical trapping, edge-enhanced microscopy, high-speed optical communication, and secure quantum teleportation to spin-orbital coupling. In a variety of OAM-involved applications, it is crucial to discern different OAM states with high fidelity. In the current paper, we review the latest research progress on OAM detection with micro- and nano-optical structures that are based on plasmonics, photonic integrated circuits (PICs), and liquid crystal devices. These innovative OAM sorters are promising to ultimately achieve the miniaturization and integration of high-fidelity OAM detectors and inspire numerous applications that harness the intriguing properties of the twisted light. Cited: Crossref(7)
 Select Laser-written three dimensional nonlinear photonic crystals Feng CHEN Front. Optoelectron..  2019, 12 (4): 342-343.   https://doi.org/10.1007/s12200-019-0982-6 Abstract   HTML   PDF (281KB)
 Select Fiber-based optical trapping and manipulation Hongbao XIN, Baojun LI Front. Optoelectron..  2019, 12 (1): 97-110.   https://doi.org/10.1007/s12200-017-0755-z Abstract   HTML   PDF (5400KB) An optical fiber serves as a versatile tool for optical trapping and manipulation owing to its many advantages over conventional optical tweezers, including ease of fabrication, compact configurations, flexible manipulation capabilities, ease of integration, and wide applicability. Here, we review recent progress in fiber-based optical trapping and manipulation, which includes mainly photothermal-based and optical-force-based trapping and manipulation. We focus on five topics in our review of progress in this area: massive photothermal trapping and manipulation, evanescent-field-based trapping and manipulation, dual-fiber tweezers for single-nanoparticle trapping and manipulation, single-fiber tweezers for single-particle trapping and manipulation, and single-fiber tweezers for multiple-particle/cell trapping and assembly. Cited: Crossref(7)
 Select Photonic crystals and topological photonics C.T. CHAN Front. Optoelectron..  2020, 13 (1): 2-3.   https://doi.org/10.1007/s12200-020-1022-2 Abstract   HTML   PDF (73KB)
 Select Spectrally efficient single carrier 400G optical signal transmission Jianjun YU Front. Optoelectron..  2019, 12 (1): 15-23.   https://doi.org/10.1007/s12200-018-0833-x Abstract   HTML   PDF (2004KB) In this paper, the recent progress on spectrally efficient single carrier (SC) 400G optical signal transmission was summarized. By using quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (16QAM) and 64QAM, we can realize transmission distance over 10000, 6000 and 3000 km, respectively, with large area fiber and all-Raman amplification. To improve the system performance and generate high-order QAM, advanced digital signal processing algorithms such as probabilistic shaping and look-up table pre-distortion are employed to improve the transmission performance. Cited: Crossref(3)
 Select Photonic crystal and topological photonics provide new modulation degrees of freedom Xiaoyong HU Front. Optoelectron..  2020, 13 (1): 1-1.   https://doi.org/10.1007/s12200-020-1021-3 Abstract   HTML   PDF (65KB)
 Select On-chip programmable pulse processor employing cascaded MZI-MRR structure Yuhe ZHAO, Xu WANG, Dingshan GAO, Jianji DONG, Xinliang ZHANG Front. Optoelectron..  2019, 12 (2): 148-156.   https://doi.org/10.1007/s12200-018-0846-5 Abstract   HTML   PDF (3413KB) Optical pulse processor meets the urgent demand for high-speed, ultra wideband devices, which can avoid electrical confinements in various fields, e.g., all-optical communication, optical computing technology, coherent control and microwave fields. To date, great efforts have been made particularly in on-chip programmable pulse processing. Here, we experimentally demonstrate a programmable pulse processor employing 16-cascaded Mach-Zehnder interferometer coupled microring resonator (MZI-MRR) structure based on silicon-on-insulator wafer. With micro-heaters loaded to the device, both amplitude and frequency tunings can be realized in each MZI-MRR unit. Thanks to its reconfigurability and integration ability, the pulse processor has exhibited versatile functions. First, it can serve as a fractional differentiator whose tuning range is 0.51−2.23 with deviation no more than 7%. Second, the device can be tuned into a programmable optical filter whose bandwidth varies from 0.15 to 0.97 nm. The optical filter is also shape tunable. Especially, 15-channel wavelength selective switches are generated. Cited: Crossref(9)
 Select Ether chain functionalized fullerene derivatives as cathode interface materials for efficient organic solar cells Jikang LIU, Junli LI, Guoli TU Front. Optoelectron..  2018, 11 (4): 348-359.   https://doi.org/10.1007/s12200-018-0842-9 Abstract   HTML   PDF (652KB) The electron transport layer (ETL) plays a crucial role on the electron injection and extraction, resulting in balanced charge transporting and reducing the interfacial energy barrier. The interface compatibility and electrical contact via employing appropriate buffer layer at the surface of hydrophobic organic active layer and hydrophilic inorganic electrode are also essential for charge collections. Herein, an ether chain functionalized fullerene derivatives [6,6]-phenyl-C61-butyricacid-(3,5-bis(2-(2-ethoxyethoxy)-ethoxy)-phenyl)-methyl ester (C60-2EPM) was developed to modify zinc oxide (ZnO) in inverted structure organic solar cells (OSCs). The composited ZnO/C60-2EPM interface layer can help to overcome the low interface compatibility between ZnO and organic active layer. By introducing the C60-2EPM layer, the composited fullerene derivatives tune energy alignment and accelerated the electronic transfer, leading to increased photocurrent and power conversion efficiency (PCE) in the inverted OSCs. The PCE based on PTB7-Th:PC71BM was enhance from 8.11% on bare ZnO to 8.38% and 8.65% with increasing concentrations of 2.0 and 4.0 mg/mL, respectively. The fullerene derivatives C60-2EPM was also used as a third compound in P3HT:PC61BM blend to form ternary system, the devices with addition of C60-2EPM exhibited better values than the control device. Cited: Crossref(4)
 Select Transmission characteristics of linearly polarized light in reflection-type one-dimensional magnetophotonic crystals Chunxiang ZENG, Zeqing WANG, Yingmao XIE Front. Optoelectron..  2019, 12 (4): 365-371.   https://doi.org/10.1007/s12200-019-0870-0 Abstract   HTML   PDF (1145KB) The propagation properties of linearly polarized light in reflection-type one-dimensional magnetophotonic crystals are studied by using the 4×4 transmission matrix method. The structure models of reflection-type one-dimensional magnetophotonic crystals are designed, the magnetic field direction control characteristics of reflection spectrum and Kerr rotation angle are discussed, and the effect of applied magnetic field direction and strength on reflection spectrum and Kerr rotation angle are analyzed. The results show that the non-diagonal elements in the dielectric constant of magneto optical materials change when the angle ϕ between applied magnetic field and optical path changes, the reflectivity and Kerr rotation angle decrease when the angle ϕ increases; when the applied magnetic field strength changes, the reflectivity and Kerr rotation angle increase when the applied magnetic field strength increases; by adjusting the angle ϕ and strength of the applied magnetic field, the rotation angle of Kerr can be adjusted to 45°, and a more flat reflection spectrum can be obtained by designing the appropriate structure.
 Select Improved offline multi-objective routing and wavelength assignment in optical networks Harpreet KAUR, Munish RATTAN Front. Optoelectron..  2019, 12 (4): 433-444.   https://doi.org/10.1007/s12200-019-0850-4 Abstract   HTML   PDF (979KB) Optical networks act as a backbone for coming generation high speed applications. These applications demand a very high bandwidth which can be exploited with the use of wavelength division multiplexing (WDM) technology. The issue of setting light paths for the traffic demands is routing and wavelength assignment (RWA) problem. Based on the type of traffic patterns, it can be categorized as offline or online RWA. In this paper, an effective solution to offline (static) routing and wavelength assignment is presented considering multiple objectives simultaneously. Initially, the flower pollination (FP) technique is utilized. Then the problem is extended with the parallel hybrid technique with flower pollination and intelligent water drop algorithm (FPIWDA). Further, FPIWD is hybrid in parallel with simulated annealing (SA) algorithm to propose a parallel hybrid algorithm FPIWDSA. The results obtained through extensive simulation show the superiority of FPIWD as compared to FP. Moreover, the results in terms of blocking probability with respect to wavelengths and load of FPIWDSA are more propitious than FP and FPIWD.
 Select Experimental and simulation assessments of underwater light propagation Fatah ALMABOUADA, Manuel Adler ABREU, João M. P. COELHO, Kamal Eddine AIADI Front. Optoelectron..  2019, 12 (4): 405-412.   https://doi.org/10.1007/s12200-019-0865-x Abstract   HTML   PDF (2058KB) This paper investigates the light propagation through several types of water by experimental and simulation. The Zemax-ray tracing software allowed to simulate the propagation of light in water and to observe the receiver response by reproducing the real conditions of propagation. The underwater environment has been reproduced by a 1.2 m long water tube and 20 cm in diameter with a glass window fitted on one side. The use of tap water with different amounts of sand leads toward three types of water with different attenuation coefficients (0.133, 0.343, 0.580 m−1). The light transmission in the three types of water was experimentally evaluated using a doubled Nd:YAG laser with energy of 4.3 mJ and a pulse width of 20 ns. Comparisons were done between simulation and experimental results.
 Select Chemical sensing through photonic crystal fiber: sulfuric acid detection Etu PODDER, Md. Bellal HOSSAIN, Rayhan Habib JIBON, Abdullah Al-Mamun BULBUL, Himadri Shekhar MONDAL Front. Optoelectron..  2019, 12 (4): 372-381.   https://doi.org/10.1007/s12200-019-0903-8 Abstract   HTML   PDF (1902KB) A photonic crystal fiber (PCF) for sensing of sulfuric acid is designed and analyzed using Comsol Multiphysics. To analyze the sensor performance, 0%, 10%, 20%, 30%, 40% H2SO4 solution is placed into the fiber separately and then relative sensitivity, confinement loss, birefringence, effective area etc. are investigated for each solution over wavelength ranging from 0.8 to 1.8 mm. The sensor structure affords moderately high relative sensitivity and around 63.4% sensitivity is achieved for the highest concentration of H2SO4 at the wavelength 1.5 mm in x polarization direction. This PCF model also shows zero confinement loss for all solutions of H2SO4 over wavelength ranging from 1 to 1.35 mm and later on approximately 1.422 × 10−17 dB/km confinement loss is found for the highest concentration of H2SO4 at 1.5 mm wavelength. Besides, higher birefringence is attained when the concentration of sulfuric acid is lower and it is achieved 7.5 × 10−4 at 1.5 mm wavelength. Moreover, higher sensing area is achieved at high concentration of sulfuric acid. Cited: Crossref(10)
 Select Ultra-flat broadband microwave frequency comb generation based on optical frequency comb with a multiple-quantum-well electro-absorption modulator in critical state Cong SHEN, Peili LI, Xinyuan ZHU, Yuanfang ZHANG, Yaqiao HAN Front. Optoelectron..  2019, 12 (4): 382-391.   https://doi.org/10.1007/s12200-019-0915-4 Abstract   HTML   PDF (2051KB) In this paper, we proposed a novel ultra-flat broadband microwave frequency comb (MFC) generation based on optical frequency comb (OFC) with a multiple-quantum-well electro-absorption modulator (MQW-EAM) in critical state. The scheme is simple and easy to adjust. The performance of the MFC generation scheme is investigated using software Optisystem. The results show that the comb spacing of MFC can be adjusted from 5 to 20 GHz by changing RF signal’s frequency and the MFC is almost independent on the linewidth of the tunable laser diode. The performance of the MFC can be improved by reasonably increasing the voltage of the RF, the small-signal gain of the Erbium-doped fiber amplifier (EDFA) and the responsivity of the photodetector. The MFC generated by this scheme has 300 GHz effective bandwidth with 15 comb lines, whose power variation is 0.02 dB, when the components’ parameters in the Optisystem are set as follows: the power of tunable laser diode (TLD) is 0 dBm, the wavelength is 1552.52 nm, and linewidth is 1 MHz; RF signal’s frequency is 20 GHz and the voltage is 10 V; the reverse bias voltage of MQW-EAM is 6.92 V; the small-signal gain of the EDFA is 40 dB; the responsivity of the photodetector (PD) is 1 A/W.
 Select Near-infrared carbon-implanted waveguides in Tb3+-doped aluminum borosilicate glasses Yue WANG, Jiaxin ZHAO, Qifeng ZHU, Jianping SHEN, Zhongyue WANG, Haitao GUO, Chunxiao LIU Front. Optoelectron..  2019, 12 (4): 392-396.   https://doi.org/10.1007/s12200-019-0869-6 Abstract   HTML   PDF (957KB) Ion implantation has played a unique role in the fabrication of optical waveguide devices. Tb3+-doped aluminum borosilicate (TDAB) glass has been considered as an important magneto-optical material. In this work, near-infrared waveguides have been manufactured by the (5.5+ 6.0) MeV C3+ ion implantation with doses of (4.0+ 8.0) × 1013 ions·cm−2 in the TDAB glass. The modes propagated in the TDAB glass waveguide were recorded by a prism-coupling system. The ﬁnite-difference beam propagation method (FD-BPM) was carried out to simulate the guiding characteristics of the TDAB glass waveguide. The TDAB glass waveguide allows the light propagation with a single-mode at 1.539 mm and can serve as a potential candidate for future waveguide isolators. Cited: Crossref(3)
 Select Heuristic polling sequence to enhance sleep count of EPON Bhargav Ram RAYAPATI, Nakkeeran RANGASWAMY Front. Optoelectron..  2019, 12 (4): 422-432.   https://doi.org/10.1007/s12200-019-0906-5 Abstract   HTML   PDF (876KB) Next-generation passive optical networks (PONs) demand power conservation to create a green environment. A reduction in power consumption of the traditional Ethernet passive optical network (EPON) can be achieved by increasing the sleep count in optical network units (ONUs). In this paper, this is accomplished by introducing a first-in-last-out (FILO) polling sequence in the place of a fixed polling sequence to increase the number of ONUs entering sleep mode (sleep count). In a fixed polling sequence, the optical line terminal (OLT) allocates idle time to the ONUs based on the overall load of the ONUs. This leads to a situation that whenever the idle time does not meet the wakeup time threshold of sleep mode, the ONUs are put into doze/active mode, which consumes more power. In the FILO polling sequence, the first polled ONU in the current cycle is made to be polled last in the following cycle. Polling continues in this way, and by this rearrangement, the idle time of delayed poll ONUs increases; hence, it helps to reduce the power consumption. Additionally, a modified load adaptive sequence arrangement (MLASA) method is suggested, where the ONUs are categorized into doze ONUs and sleep ONUs. A numerical simulation of the FILO polling sequence with a vertical cavity surface emitting laser (VCSEL) ONU shows a maximum reduction in power consumption of 15.5 W and a 20% improvement in energy savings compared with the traditional fixed polling sequence. The MLASA method results in better power consumption with minimum delay than that of the proposed FILO and existing LASA methods.
 Select Review on partially coherent vortex beams Jun ZENG, Rong LIN, Xianlong LIU, Chengliang ZHAO, Yangjian CAI Front. Optoelectron..  2019, 12 (3): 229-248.   https://doi.org/10.1007/s12200-019-0901-x Abstract   HTML   PDF (9863KB) Ever since vortex beams were proposed, they are known for owning phase singularity and carrying orbital angular momentum (OAM). In the past decades, coherent optics developed rapidly. Vortex beams have been extended from fully coherent light to partially coherent light, from scalar light to vector light, from integral topological charge (TC) to fractional TC. Partially coherent vortex beams have attracted tremendous interest due to their hidden correlation singularity and unique propagation properties (e.g., beam shaping, beam rotation and self-reconstruction). Based on the sufficient condition for devising a genuine correlation function of partially coherent beam, partially coherent vortex beams with nonconventional correlation functions (i.e., non-Gaussian correlated Schell-model functions) were introduced recently. This timely review summarizes basic concepts, theoretical models, generation and propagation of partially coherent vortex beams. Cited: Crossref(7)
 Select Robot visual guide with Fourier-Mellin based visual tracking Chao PENG, Danhua CAO, Yubin WU, Qun YANG Front. Optoelectron..  2019, 12 (4): 413-421.   https://doi.org/10.1007/s12200-019-0862-0 Abstract   HTML   PDF (3230KB) Robot vision guide is an important research area in industrial automation, and image-based target pose estimation is one of the most challenging problems. We focus on target pose estimation and present a solution based on the binocular stereo vision in this paper. To improve the robustness and speed of pose estimation, we propose a novel visual tracking algorithm based on Fourier-Mellin transform to extract the target region. We evaluate the proposed tracking algorithm on online tracking benchmark-50 (OTB-50) and the results show that it outperforms other lightweight trackers, especially when the target is rotated or scaled. The final experiment proves that the improved pose estimation approach can achieve a position accuracy of 1.84 mm and a speed of 7 FPS (frames per second). Besides, this approach is robust to the variances of illumination and can work well in the range of 250-700 lux. Cited: Crossref(3)
 Select Two-dimensional material functional devices enabled by direct laser fabrication Tieshan YANG, Han LIN, Baohua JIA Front. Optoelectron..  2018, 11 (1): 2-22.   https://doi.org/10.1007/s12200-017-0753-1 Abstract   HTML   PDF (1167KB) During the past decades, atomically thin, two-dimensional (2D) layered materials have attracted tremendous research interest on both fundamental properties and practical applications because of their extraordinary mechanical, thermal, electrical and optical properties, which are distinct from their counterparts in the bulk format. Various fabrication methods, such as soft-lithography, screen-printing, colloidal-templating and chemical/dry etching have been developed to fabricate micro/nanostructures in 2D materials. Direct laser fabrication with the advantages of unique three-dimensional (3D) processing capability, arbitrary-shape designability and high fabrication accuracy up to tens of nanometers, which is far beyond the optical diffraction limit, has been widely studied and applied in the fabrication of various micro/nanostructures of 2D materials for functional devices. This timely review summarizes the laser-matter interaction on 2D materials and the significant advances on laser-assisted 2D materials fabrication toward diverse functional photonics, optoelectronics, and electrochemical energy storage devices. The perspectives and challenges in designing and improving laser fabricated 2D materials devices are discussed as well. Cited: Crossref(18)
 Select Distributed feedback organic lasing in photonic crystals Yulan FU, Tianrui ZHAI Front. Optoelectron..  2020, 13 (1): 18-34.   https://doi.org/10.1007/s12200-019-0942-1 Abstract   HTML   PDF (3014KB) Considerable research efforts have been devoted to the investigation of distributed feedback (DFB) organic lasing in photonic crystals in recent decades. It is still a big challenge to realize DFB lasing in complex photonic crystals. This review discusses the recent progress on the DFB organic laser based on one-, two-, and three-dimensional photonic crystals. The photophysics of gain materials and the fabrication of laser cavities are also introduced. At last, future development trends of the lasers are prospected. Cited: Crossref(4)
 Select Airy-like field under high numerical aperture optical system Yong LIU, Zhifeng ZHANG, Cuifang KUANG Front. Optoelectron..  2019, 12 (4): 397-404.   https://doi.org/10.1007/s12200-019-0866-9 Abstract   HTML   PDF (3486KB) The tightly focused field of an incident light beam through cubic phase modulation has been investigated by vectorial diffraction theory. For different modulation index of cubic phase and polarization states of the incident light, the focused fields have been presented. The results show that the Airy-like field can be produced by cubic phase modulation under high numerical aperture (NA) optical system. Intensity pattern and length of the main lobe are depended on modulation index for the spatial uniform polarization, and the Airy-like field is affected by polarization state for the spatial nonuniform polarization. It is helpful to structure new optical fields in optical manipulation, optical imaging, and surface plasma controlling.
 Select Modulation of orbital angular momentum on the propagation dynamics of light fields Peng LI, Sheng LIU, Yi ZHANG, Lei HAN, Dongjing WU, Huachao CHENG, Shuxia QI, Xuyue GUO, Jianlin ZHAO Front. Optoelectron..  2019, 12 (1): 69-87.   https://doi.org/10.1007/s12200-017-0743-3 Abstract   HTML   PDF (8624KB) Optical vortices carrying orbital angular momentum (OAM) have attracted extensive attention in recent decades because of their interesting applications in optical trapping, optical machining, optical communication, quantum information, and optical microscopy. Intriguing effects induced by OAMs, such as angular momentum conversion, spin Hall effect of light (SHEL), and spin–orbital interaction, have also gained increasing interest. In this article, we provide an overview of the modulations of OAMs on the propagation dynamics of scalar and vector fields in free space. First, we introduce the evolution of canonical and noncanonical optical vortices and analyze the modulations by means of local spatial frequency. Second, we review the Pancharatnam–Berry (PB) phases arising from spin–orbital interaction and reveal the control of beam evolution referring to novel behavior such as spin-dependent splitting and polarization singularity conversion. Finally, we discuss the propagation and focusing properties of azimuthally broken vector vortex beams. Cited: Crossref(4)
 Select Exciton polaritons based on planar dielectric Si asymmetric nanogratings coupled with J-aggregated dyes film Zhen CHAI, Xiaoyong HU, Qihuang GONG Front. Optoelectron..  2020, 13 (1): 4-11.   https://doi.org/10.1007/s12200-019-0940-3 Abstract   HTML   PDF (1174KB) Optical cavity polaritons, originated from strong coupling between the excitons in materials and photons in the confined cavities field, have recently emerged as their applications in the high-speed low-power polaritons devices, low-threshold lasing and so on. However, the traditional exciton polaritons based on metal plasmonic structures or Fabry-Perot cavities suffer from the disadvantages of large intrinsic losses or hard to integrate and nanofabricate. This greatly limits the applications of exciton poalritons. Thus, here we implement a compact low-loss dielectric photonic – organic nanostructure by placing a 2-nm-thick PVA doped with TDBC film on top of a planar Si asymmetric nanogratings to reveal the exciton polaritons modes. We find a distinct anti-crossing dispersion behavior appears with a 117.16 meV Rabi splitting when varying the period of Si nanogratings. Polaritons dispersion and mode anti-crossing behaviors are also observed when considering the independence of the height of Si, width of Si nanowire B, and distance between the two Si nanowires in one period. This work offers an opportunity to realize low-loss novel polaritons applications. Cited: Crossref(3)