Research advances in optoelectronic devices of quantum dot-polymer nanocomposites
Chen Xingfan, Li Bin, Li Xueming, and Tang Libin
Quantum dots have attracted much attention in recent years because of their excellent photoelectric properties. However, the large-scale application of quantum dots has yet to be developed due to its processing technology and stability. The emergence of quantum dot-polymer nanocomposites effectively makes up for this problem. It is an effective method to solve the current application problems of quantum dots by disperses quantum dots into organic polymers to form nanocomposites and integrates the respective advantages of quantum dots and polymers. It has significant development potential. The main preparation technology of quantum dots was introduced, on this basis, the preparation methods of QD-polymer composites and their applications in lasers, light emitting diodes, photodetectors, QD-TVs and other optoelectronic devices were summarized, and finally its application in the field of optoelectronic device was prospected.
  • Jun. 14, 2022
  • Infrared and Laser Engineering
  • Vol. 51 Issue 5 20210637 (2022)
  • DOI:10.3788/IRLA20210637
Effects of isolation trough on cleavage of InSb chip in InSb detector
Tian Xiaohan, Zhang Jiangfeng, Zhang Xiaoling, and Meng Qingduan
Local cleavage of indium antimonide (InSb) chips restricts the improvement of the yield of InSb infrared focal plane detectors (IRFPAs) under cyclic liquid nitrogen shocking tests. Stress concentration effect may appear in isolation troughs surrounding mesa-junction photosensitive units, drives the dislocation line to nucleate and to propagate, ultimately to punch through InSb chips. In order to analyze quantitatively the influence of isolation troughs on the cleavage of the InSb chip, a structural model of InSb IRFPAs was established, and the in-plane normal stress distribution on the InSb front surface was obtained. Stress concentration phenomena appear on the bottom of V-shaped isolation trough added. Then, the assumed initial cracks with different lengths at the bottom of V-shaped isolation trough were put, here the preset initial cracks were employed to describe dislocation lines in InSb wafers, and were perpendicular to the InSb chips, and obtained the relationship between the energy release rates and the preset crack length. After analyzing these results, the in-plane stress concentration phenomena appears exactly at the bottom of V-shaped isolation trough, and originates from the added V-shaped isolation trough; the enlarged stress at the bottom of V-shaped isolation trough could drive the dislocation lines in the InSb chip to grow and to punch through the InSb chip, thus, the macro cleavage of InSb chip is created; once the preset cracks connect directly with the bottom of V-shaped isolation trough, cleavage of InSb chips is more likely to appear. All these conclusions provide a new perspective to understand the cleavage of InSb chips.
  • Jun. 14, 2022
  • Infrared and Laser Engineering
  • Vol. 51 Issue 5 20210599 (2022)
  • DOI:10.3788/IRLA20210599
Design and fabrication of polarization and phase modulated beam splitter
Pan Yonggang, Zhang Sibao, Liu Zheng, Liu Wencheng, Li Mian, Zhang Chunjuan, and Luo Changxin
Polarization and phase controlled beam splitter is an indispensable optical element in free space quantum communication system. Its performance directly affects the communication quality and determines the communication error rate. Based on the theory of equivalent layer design, the special film structure of ''dielectric+metal+dielectric'' is adopted, and Ag metal material and SiO2, Al2O3, Ta2O5 dielectric material are selected to realize 45° incident angle on quartz substrate, and the average transmittance/reflectance ratio is 8.5: 91.5 in the wavelength range from 1500 nm to 1600 nm. Phase is controlled at 1530, 1540, 1550, 1560 nm. By optimizing the deposition process, the splitter film samples are prepared by electron beam evaporation with ion assisted technology. The test results show that the average transmittance/reflectance ratio is 8.53: 91.47 in the wavelength range of 1500-1600 nm under the condition of 45° incidence. The transmitted phase difference controlled within 5.02° and the reflected phase controlled with 8.05° in the range of 1530, 1540, 1550, 1560 nm, which meets the requirements of spectral energy splitting ratio and phase control of communication system. In addition, the film passed the corresponding environmental test, which meets the reliability requirements.
  • Jun. 14, 2022
  • Infrared and Laser Engineering
  • Vol. 51 Issue 5 20210512 (2022)
  • DOI:10.3788/IRLA20210512
Optical fiber Michelson interference sensor for measuring refractive index
Zheng Chen, Feng Wenlin, He Sijie, and Li Bangxing
A refractive index sensor based on single-mode fiber (SMF) four-core fiber (FCF) and thin-core fiber (TCF) is proposed, forming a SMF-FCF-TCF Michelson interference structure. The optical fibers are spliced by direct splicing. Because of the mismatch of the diameter of the optical fibers’ cores, light excitation and coupling will be induced at the splicing part. The end face of the TCF is coated with a layer of silver film and protected with ultraviolet curing glue to enhance the reflectivity of the light at the end face. The four-core fiber is used as a coupler in the sensing structure, which excites more light into the cladding of the TCF, improving the sensitivity of the sensor. The refractive index and temperature sensing characteristics of the sensor were investigated experimentally. The experimental results show that the sensitivity in the refractive index range of 1.3333 to 1.3794 is 137.317 nm/RIU, the linearity is 0.999, and the temperature has little effect on the sensor. The sensing structure has a simple welding method and has certain application prospects in the field of refractive index measurement.
  • Jun. 14, 2022
  • Infrared and Laser Engineering
  • Vol. 51 Issue 5 20210327 (2022)
  • DOI:10.3788/IRLA20210327
Prediction analysis of subsurface damage of work-part ZnS in fixed abrasive lapping
Zhang Yufei, Wang Zikun, Hu Weidong, Niu Fengli, and Zhu Yongwei
The subsurface damage of workpiece formed in lapping and polishing process is the main reference to evaluate the quality of processing technology and decide the machining allowance. Therefore, the accurate prediction of subsurface damage is helpful to improve the machining efficiency. Discrete element method (DEM) was used to simulate the subsurface damage of the fixed abrasive lapping process of typical soft and brittle material ZnS, and the depth of subsurface microcrack layer after diamond machining with different particle sizes was predicted. The angle polishing method was used to polish the workpiece to an inclined plane as the sub surface damage observation plane. The corrosion of hydrochloric acid makes the subsurface microcracks appear. Under the metallographic microscope, the end point of microcracks disappearance was found and converted into the depth of subsurface microcrack layer, and the simulation results were verified by experiments. The results show that the predicted values of the depth of subsurface microcrack layer caused by grain size of 5 μm, 15 μm, 25 μm and 30 μm are 2.28 μm, 3.62 μm, 5.93 μm and 7.82 μm respectively, and the measured values of angle polishing method are 2.02 μm, 3.98 μm, 6.27 μm and 8.27 μm respectively. The results show that the wear particle size has a great influence on the subsurface damage of ZnS. With the increase of wear particle size, the depth and number of micro cracks increase. The deviation between predicted value of discrete element method and measured value is 5% - 15%. The subsurface damage of soft and brittle material ZnS after processing can be accurately predicted by using the discrete element method, which provides a reference for the formulation of polishing process.
  • Jun. 14, 2022
  • Infrared and Laser Engineering
  • Vol. 51 Issue 5 20210303 (2022)
  • DOI:10.3788/IRLA20210303
Annular Plasma Photonic Crystals with Different Filling Ratios in Dielectric Barrier Discharge
Liu Yining, Fan Weili, Hou Xiaohan, Wu Zhicheng, He Yafeng, and Liu Fucheng
Herein, we present a systematic study on annular plasma photonic crystals (APPCs) with different filling ratios in dielectric barrier discharge using the water electrodes. In this study, the APPCs with dynamically adjustable plasma columns and high spatiotemporal symmetry have been realized, providing possibilities for modulating the microstructures of elements in APPCs. Based on the experimental results, the dispersion relation of different APPCs are studied using the finite element method. Furthermore, the influences of the radius of plasma columns on the positions and sizes of band gaps are analyzed. The results show that band gaps change from unidirectional to omnidirectional with increasing plasma column radius and the widths of omnidirectional band gaps increase considerably. Compared with conventional plasma photonic crystals (PPCs), APPCs can easily produce large omnidirectional band gaps with lower threshold values of the plasma column radius. Additionally, for a given radius, the sizes of band gaps in APPCs are larger than those in conventional PPCs. The novel APPCs with tunable filling ratios proposed here provide more possibilities for engineering the band gaps and offer enlightenment for designing new types of tunable photonic crystals and developing wide band gaps, highly-integrated photonic devices.
  • Jun. 09, 2022
  • Laser & Optoelectronics Progress
  • Vol. 59 Issue 13 1323002 (2022)
  • DOI:10.3788/LOP202259.1323002
Deep Learning Architecture and Neural Network Optimization of Ultra-Wideband Antenna Modeling
Nan Jingchang, Du Youyi, Wang Minghuan, and Gao Mingming
To speed up the optimization of antenna modeling, this paper proposes a novel deep multi-layer perceptron (DMLP) network based on deep learning network architecture for optimizing ultra-wideband antenna. The DMLP network uses a step-down, connected-layer deep network, and the Adam optimizer automatically updates the learning rate. Dropout technology is used to remove random neurons in the hidden layer, preventing overfitting due to the deep network layers. This paper uses the DMLP network to model the geometric parameters of the ultra-wideband stepped microstrip monopole antenna, extracts features from the eight geometric parameters of the antenna, and predicts the S11 value of the antenna. The experimental results show that compared with traditional multilayer perceptron and radial-basis-function neural networks, the average prediction error of S11 is reduced by 118.32% and 123.76%, respectively, and it has a higher prediction accuracy. In addition, the fitting speed is improved. The feasibility of this network is verified through experiments.
  • Jun. 09, 2022
  • Laser & Optoelectronics Progress
  • Vol. 59 Issue 13 1323001 (2022)
  • DOI:10.3788/LOP202259.1323001
Design of Wide-Angle, High-Absorption Metamaterial Absorber Based on Improved Particle Swarm Optimization Algorithm
Zhou Yao, Sun Jun, Peng Yi, Sun Lei, and Dai Shuhao
The performance of metamaterial absorbers can be affected by the incident angle of electromagnetic waves, and it is difficult to design metamaterial absorbers with wide-angle stability. The traditional method relies on artificial design and optimization, which limited by its difficulty and long cycle. According to the target design’s characteristics, we design a wide-angle and high-absorptivity metamaterial absorber based on the improved particle swarm optimization algorithm. Dynamic weights and Gaussian errors are added to resolve the problem of weak local search ability in the later stage of binary particle swarm optimization algorithm. To achieve wide-angle and high-absorptivity characteristics of the absorber, the improved binary particle swarm optimization algorithm is used to optimize the structure of discrete metal blocks coded with 0 and 1 on the surface of the absorber. The simulation results show that the designed metamaterial absorber has a high absorptivity of greater than 90% from 9.4-13.3 GHz, and perfect absorption, i.e., absorptivity exceeds 99%, is obtained in the broadband of 11.6-12.6 GHz. Moreover, the absorption remains above 80%, even for the incidence angles of up to 60° under both transverse electric and transverse magnetic polarizations. This design method overcomes the shortcomings of the traditional design method and demonstrates the unique advantages of on-demand design without human intervention in the design process. This technique has broad application prospects in related fields.
  • Jun. 09, 2022
  • Laser & Optoelectronics Progress
  • Vol. 59 Issue 11 1123002 (2022)
  • DOI:10.3788/LOP202259.1123002
Design of Laser Communication Optical Transceiver Based on Double Wedge Prisms
Xing Zhenchong, and Wang Wei
With the popularization of laser communication to the platforms with limited load capacity, laser communication system is developing towards lightweight and miniaturization. As a key role of laser communication, the design of scanning and acquisition unit is also need to be lightweight and miniaturized. In this paper, first, the double wedge prisms based scanning and acquisition unit abandons the conventional mechanical servo structure, which realizes beam deflection in large field of view by independently rotating the prisms around the common rotation axis. Then, the beam deflection model and the scanning pattern model of double wedge prisms are established by using non-paraxial ray tracing method, and the scanning mode of the double wedge prisms is analyzed, which provides a certain reference for the development of light and miniaturized laser communication optical transceivers. Finally, the design and application of a kind of light-weighted and miniaturized laser communication optical terminal is proposed and analyzed based on rotating double wedge prisms and quadrant detector multiplexing technology.
  • Jun. 09, 2022
  • Laser & Optoelectronics Progress
  • Vol. 59 Issue 11 1123001 (2022)
  • DOI:10.3788/LOP202259.1123001
Neural network-based surrogate model for inverse design of metasurfaces
Guoqing Jing, Peipei Wang, Haisheng Wu, Jianjun Ren, Zhiqiang Xie, Junmin Liu, Huapeng Ye, Ying Li, Dianyuan Fan, and Shuqing Chen
Metasurfaces composed of spatially arranged ultrathin subwavelength elements are promising photonic devices for manipulating optical wavefronts, with potential applications in holography, metalens, and multiplexing communications. Finding microstructures that meet light modulation requirements is always a challenge in designing metasurfaces, where parameter sweep, gradient-based inverse design, and topology optimization are the most commonly used design methods in which the massive electromagnetic iterations require the design computational cost and are sometimes prohibitive. Herein, we propose a fast inverse design method that combines a physics-based neural network surrogate model (NNSM) with an optimization algorithm. The NNSM, which can generate an accurate electromagnetic response from the geometric topologies of the meta-atoms, is constructed for electromagnetic iterations, and the optimization algorithm is used to search for the on-demand meta-atoms from the phase library established by the NNSM to realize an inverse design. This method addresses two important problems in metasurface design: fast and accurate electromagnetic wave phase prediction and inverse design through a single phase-shift value. As a proof-of-concept, we designed an orbital angular momentum (de)multiplexer based on a phase-type metasurface, and 200 Gbit/s quadrature-phase shift-keying signals were successfully transmitted with a bit error rate approaching 1.67×10-6. Because the design is mainly based on an optimization algorithm, it can address the “one-to-many” inverse problem in other micro/nano devices such as integrated photonic circuits, waveguides, and nano-antennas.
  • May. 20, 2022
  • Photonics Research
  • Vol. 10 Issue 6 06001462 (2022)
  • DOI:10.1364/PRJ.450564