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2024,
48(6):
771-776.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.001
Abstract:
In order to develop a near-infrared band fiber grating external cavity semiconductor laser for quantum precision measurement applications, a high polarization dependent gain chip and a birefringent fiber Bragg grating were designed independently, the effects of grating reflectivity, external cavity, and chip length on laser linewidth were systematically analyzed based on the Fabry-Pérot equivalent resonant cavity model. The results showe that the developed laser achieves an output power of 54.46 mW, a side mode suppression ratio of 58.88 dB, and a polarization extinction ratio of 24.46 dB. The Lorentz linewidth measured is 2.69 kHz by delayed self-heterodyne beat frequency method. This study provides a reference for the single frequency narrow linewidth external cavity semiconductor lasers with independent design and preparation of discrete devices, and is expected to be used in quantum precision measurement fields such as radar imaging, gyroscopes, magnetometers, and atomic clocks.
In order to develop a near-infrared band fiber grating external cavity semiconductor laser for quantum precision measurement applications, a high polarization dependent gain chip and a birefringent fiber Bragg grating were designed independently, the effects of grating reflectivity, external cavity, and chip length on laser linewidth were systematically analyzed based on the Fabry-Pérot equivalent resonant cavity model. The results showe that the developed laser achieves an output power of 54.46 mW, a side mode suppression ratio of 58.88 dB, and a polarization extinction ratio of 24.46 dB. The Lorentz linewidth measured is 2.69 kHz by delayed self-heterodyne beat frequency method. This study provides a reference for the single frequency narrow linewidth external cavity semiconductor lasers with independent design and preparation of discrete devices, and is expected to be used in quantum precision measurement fields such as radar imaging, gyroscopes, magnetometers, and atomic clocks.
2024,
48(6):
777-789.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.002
Abstract:
Vertical-cavity surface-emitting laser (VCSEL) usually adopt a 2-D array structure with small-sized light-emitting cells in parallel to increase the output optical power and to improve the laser beam quality. However, with the down scaling of the chip size and the increasing of the array integration, the self-heating effect caused by the power dissipation of the VCSEL cell and the thermal coupling effect among VCSEL cells will lead to a sharp increase in the junction temperature of the VCSEL array. Due to the effect of thermal-opto-electro feedback, the optical performance and thermal reliability of the VCSEL array will be limited seriously, which propose urgent requirements for the thermal design of the VCSEL array. Based on the heat generation mechanism of VSCEL array, latest development of VCSEL array thermal design was reviewed in detail from the aspects of thermal-opto-electro modeling and thermal design methodology. The development trend of thermal design in VCSEL array was also prospected.
Vertical-cavity surface-emitting laser (VCSEL) usually adopt a 2-D array structure with small-sized light-emitting cells in parallel to increase the output optical power and to improve the laser beam quality. However, with the down scaling of the chip size and the increasing of the array integration, the self-heating effect caused by the power dissipation of the VCSEL cell and the thermal coupling effect among VCSEL cells will lead to a sharp increase in the junction temperature of the VCSEL array. Due to the effect of thermal-opto-electro feedback, the optical performance and thermal reliability of the VCSEL array will be limited seriously, which propose urgent requirements for the thermal design of the VCSEL array. Based on the heat generation mechanism of VSCEL array, latest development of VCSEL array thermal design was reviewed in detail from the aspects of thermal-opto-electro modeling and thermal design methodology. The development trend of thermal design in VCSEL array was also prospected.
2024,
48(6):
790-798.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.003
Abstract:
Going through three important iterations, semiconductor material systems have been widely used in important fields such as microelectronics, communications, artificial intelligence, and carbon neutrality. With the rapid development of technologies, the research ona new generation of high-performance semiconductor materials and devices has become the focus of international anvanced technology. As one of the most promising fourth-generation semiconductor material, antimonide semiconductor materials have unique advantages andbroad application prospects in developingnext-generation high-performance, small-volume, low-power, and low-cost infrared optoelectronic devices. In this paper, the development process and research status of antimonide semiconductor lasers at home and abroad were reviewed, the key issues such as design of device structure, material epitaxial growth, mode selection and wavelength expansion were analyzed, high-performance antimonide quantum well lasers have been grown by molecular beam epitaxy technology. The design scheme and key technology for realizing high-power, single-mode and high-beam quality antimonide lasers were emphasized, and the research prospect of single-mode antimonide lasers with excellent characteristics such as low cost, high yield and high power was predicted.
Going through three important iterations, semiconductor material systems have been widely used in important fields such as microelectronics, communications, artificial intelligence, and carbon neutrality. With the rapid development of technologies, the research ona new generation of high-performance semiconductor materials and devices has become the focus of international anvanced technology. As one of the most promising fourth-generation semiconductor material, antimonide semiconductor materials have unique advantages andbroad application prospects in developingnext-generation high-performance, small-volume, low-power, and low-cost infrared optoelectronic devices. In this paper, the development process and research status of antimonide semiconductor lasers at home and abroad were reviewed, the key issues such as design of device structure, material epitaxial growth, mode selection and wavelength expansion were analyzed, high-performance antimonide quantum well lasers have been grown by molecular beam epitaxy technology. The design scheme and key technology for realizing high-power, single-mode and high-beam quality antimonide lasers were emphasized, and the research prospect of single-mode antimonide lasers with excellent characteristics such as low cost, high yield and high power was predicted.
2024,
48(6):
799-808.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.004
Abstract:
Semiconductor lasers in the near-infrared wavelength range based on GaAs substrates have made significant advancements. In the realm of high-power research, the tapered semiconductor lasers with a master-oscillator power-amplifier structure have garnered widespread attention due to its excellent characteristics, allowing for the simultaneous achievement of high power and high beam quality. The representative research results on GaAs-based tapered lasers at home and abroad in recent years were summarized, and the progresses in theoretical studies and experiments on the design of laser device structures (including the design of ridge and tapered regions as well as Bragg gratings) and the optimization of epitaxial layers were discussed. Focusing on the demands for high power, high beam quality, high brightness, and narrow linewidth applications, the research progress and performance characteristics of tapered lasers were summarized. The research work of the tapered lasers was briefly introduced. Furthermore, an outlook on the future development directions of tapered semiconductor lasers has been provided.
Semiconductor lasers in the near-infrared wavelength range based on GaAs substrates have made significant advancements. In the realm of high-power research, the tapered semiconductor lasers with a master-oscillator power-amplifier structure have garnered widespread attention due to its excellent characteristics, allowing for the simultaneous achievement of high power and high beam quality. The representative research results on GaAs-based tapered lasers at home and abroad in recent years were summarized, and the progresses in theoretical studies and experiments on the design of laser device structures (including the design of ridge and tapered regions as well as Bragg gratings) and the optimization of epitaxial layers were discussed. Focusing on the demands for high power, high beam quality, high brightness, and narrow linewidth applications, the research progress and performance characteristics of tapered lasers were summarized. The research work of the tapered lasers was briefly introduced. Furthermore, an outlook on the future development directions of tapered semiconductor lasers has been provided.
2024,
48(6):
809-815.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.005
Abstract:
In order to compare the effects of different types of quenching circuits on the detection performance of 4H-SiC avalanche photodiodes (APD), single-photon detection experiments were conducted on two types of SiC ultraviolet APD by using passive quenching circuits (PQC) and active quenching circuits (AQC). It was found that during a long dead time in PQC, post pulse phenomena occur frequently, resulting in a higher dark counting rate (DCR) of APD, thereby reducing the signal-to-noise ratio of the device. A study was conducted on the time distribution of pulse probability after APD, and further analysis was conducted on the problems encountered by AQC in single-photon detection under higher device bias. A circuit improvement plan was proposed. The research results indicate that by adjusting the dead time of AQC to 45 ns, the device DCR can be reduced to 1/4 of the original level under the same single-photon detection efficiency. By effectively suppressing post pulse and accelerating APD recovery speed, AQC can enable the device to exhibit superior detection performance. This study provides a certain reference for the application of SiC APD in single-photon detection.
In order to compare the effects of different types of quenching circuits on the detection performance of 4H-SiC avalanche photodiodes (APD), single-photon detection experiments were conducted on two types of SiC ultraviolet APD by using passive quenching circuits (PQC) and active quenching circuits (AQC). It was found that during a long dead time in PQC, post pulse phenomena occur frequently, resulting in a higher dark counting rate (DCR) of APD, thereby reducing the signal-to-noise ratio of the device. A study was conducted on the time distribution of pulse probability after APD, and further analysis was conducted on the problems encountered by AQC in single-photon detection under higher device bias. A circuit improvement plan was proposed. The research results indicate that by adjusting the dead time of AQC to 45 ns, the device DCR can be reduced to 1/4 of the original level under the same single-photon detection efficiency. By effectively suppressing post pulse and accelerating APD recovery speed, AQC can enable the device to exhibit superior detection performance. This study provides a certain reference for the application of SiC APD in single-photon detection.
2024,
48(6):
816-821.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.006
Abstract:
In order to improve the dynamic range of the infrared readout circuit and enhance the quality of infrared imaging, a high-performance infrared readout circuit with a four-pixel time-sharing capacitive feedback transimpedance amplifier (CTIA) and a bandgap reference source were designed by adding a dark current suppression module circuit. Two reference voltages of 586 mV and 293 mV were generated by bandgap reference source. Among them, the temperature drift coefficient of the reference voltage value of 293 mV reaches 1.49×10-6/℃, which can provide stable voltage bias for the gate and source of the shunt tube to achieve accurate skim of the dark current. The results show that a wide dynamic range of integral voltage readout of current signals from 10 pA to 10 nA can be realized, and the readout data are fitted by a linear fit with a goodness of fit (R2) of 0.9992, which indicates that the circuit performs well. This study can be applied in the future to linear array and focal plane array infrared detectors.
In order to improve the dynamic range of the infrared readout circuit and enhance the quality of infrared imaging, a high-performance infrared readout circuit with a four-pixel time-sharing capacitive feedback transimpedance amplifier (CTIA) and a bandgap reference source were designed by adding a dark current suppression module circuit. Two reference voltages of 586 mV and 293 mV were generated by bandgap reference source. Among them, the temperature drift coefficient of the reference voltage value of 293 mV reaches 1.49×10-6/℃, which can provide stable voltage bias for the gate and source of the shunt tube to achieve accurate skim of the dark current. The results show that a wide dynamic range of integral voltage readout of current signals from 10 pA to 10 nA can be realized, and the readout data are fitted by a linear fit with a goodness of fit (R2) of 0.9992, which indicates that the circuit performs well. This study can be applied in the future to linear array and focal plane array infrared detectors.
2024,
48(6):
822-831.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.007
Abstract:
Type-Ⅱsuperlattice (T2SL) infrared detector has high sensitivity and fast response speed, which is suitable for longer distance imaging and higher speed tracking of moving targets. Quantum efficiency (QE) is one of the key indicators to determine whether the photodetector can achieve high quality imaging, so it is of great significance to improve the QE of T2SL infrared detector. In order to have a more intuitive understanding of how T2SL infrared detector QE can be improved, the methods to improve QE of mid-long wave T2SL infrared detector were reviewed, and the extent to which QE can be achieved under different regulatory means were summarized. The effects of band structure design, absorption layer thickness setting, absorption layer doping type selection and material improvement on QE of T2SL infrared detectors are discussed, and the research status and future development of high QE of T2SL infrared detectors are also prospected.
Type-Ⅱsuperlattice (T2SL) infrared detector has high sensitivity and fast response speed, which is suitable for longer distance imaging and higher speed tracking of moving targets. Quantum efficiency (QE) is one of the key indicators to determine whether the photodetector can achieve high quality imaging, so it is of great significance to improve the QE of T2SL infrared detector. In order to have a more intuitive understanding of how T2SL infrared detector QE can be improved, the methods to improve QE of mid-long wave T2SL infrared detector were reviewed, and the extent to which QE can be achieved under different regulatory means were summarized. The effects of band structure design, absorption layer thickness setting, absorption layer doping type selection and material improvement on QE of T2SL infrared detectors are discussed, and the research status and future development of high QE of T2SL infrared detectors are also prospected.
2024,
48(6):
832-837.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.008
Abstract:
In order to avoid the saturation phenomenon of output optical power of all silicon optical phased array (OPA) and the low phase shifting efficiency of silicon nitride, a design concept combining silicon and silicon nitride was adopted, which ensured the phase shifting efficiency while achieving high power input. In addition, in order to avoid phase noise caused by mutual coupling between channels, silicon-based integrated OPA had waveguide spacing greater than half wavelength, which led to the presence of gate lobes and limited the scanning range. To solve this problem, a silicon waveguide was used as the input waveguide in front of the antenna to reduce the array elements spacing. The results show that, the chip ultimately achieves a scanning range of 41°×7.4° and a chip loss of 10.7 dB. This study is helpful for further improvement of OPA chips.
In order to avoid the saturation phenomenon of output optical power of all silicon optical phased array (OPA) and the low phase shifting efficiency of silicon nitride, a design concept combining silicon and silicon nitride was adopted, which ensured the phase shifting efficiency while achieving high power input. In addition, in order to avoid phase noise caused by mutual coupling between channels, silicon-based integrated OPA had waveguide spacing greater than half wavelength, which led to the presence of gate lobes and limited the scanning range. To solve this problem, a silicon waveguide was used as the input waveguide in front of the antenna to reduce the array elements spacing. The results show that, the chip ultimately achieves a scanning range of 41°×7.4° and a chip loss of 10.7 dB. This study is helpful for further improvement of OPA chips.
2024,
48(6):
838-845.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.009
Abstract:
The effect of intrinsic defect types and concentrations on the behaviors of exciton transitions and carrier transports in ZnO was investigated. The intrinsic acceptor-rich ZnO (A-ZnO) microtubes were grown by the developed optical vapor supersaturation precipitation. The oxygen growth carries gas (O2) was used to realize the regulation of donor acceptor pair and neutral acceptor bound exciton A0X concentrations. The negative thermal quenching phenomenon was attributed to the middle energy state dominated by the defect concentrations. The abundant shallow acceptor concentrations and the middle energy state shifting up result in the electrical resistivity reduction by 7 times and the response time decreasing by 51% compared with the A-ZnO microtubes grown in air, leading to the high-efficient ultraviolet detector with high electrical resistivity. The present work provides a novel platform to optimize ZnO-micro/nanostructures-based optoelectronic devices.
The effect of intrinsic defect types and concentrations on the behaviors of exciton transitions and carrier transports in ZnO was investigated. The intrinsic acceptor-rich ZnO (A-ZnO) microtubes were grown by the developed optical vapor supersaturation precipitation. The oxygen growth carries gas (O2) was used to realize the regulation of donor acceptor pair and neutral acceptor bound exciton A0X concentrations. The negative thermal quenching phenomenon was attributed to the middle energy state dominated by the defect concentrations. The abundant shallow acceptor concentrations and the middle energy state shifting up result in the electrical resistivity reduction by 7 times and the response time decreasing by 51% compared with the A-ZnO microtubes grown in air, leading to the high-efficient ultraviolet detector with high electrical resistivity. The present work provides a novel platform to optimize ZnO-micro/nanostructures-based optoelectronic devices.
2024,
48(6):
846-855.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.010
Abstract:
Photodetecting based on two-dimensional (2-D) material is an important trend for new generation of photodetection technology. Free of lattice matching, 2-D materials can be easily combined via van der Waals (VDW) force to materials of other dimensions, such as zero-dimensional (0-D) quantum dots, one-dimensional (1-D) nanowires and three-dimensional (3-D) semiconductors, to form hetero-dimension (HD) photodetectors. So far, significant progresses have been made for 2-D material based HD photodetectors to exhibit obviously higher performance than 2-D material photodetectors. The merits of VDW HD junctions in photodetection are introduced in this paper, and the photodetector research achievements of the HD styles including 2D-0D, 2D-1D, 2D-3D, and multi-layer multi-dimension are reviewed. Some insight into the possible challenges and future prospects of 2-D materials based HD-structure photodetectors is attempted.
Photodetecting based on two-dimensional (2-D) material is an important trend for new generation of photodetection technology. Free of lattice matching, 2-D materials can be easily combined via van der Waals (VDW) force to materials of other dimensions, such as zero-dimensional (0-D) quantum dots, one-dimensional (1-D) nanowires and three-dimensional (3-D) semiconductors, to form hetero-dimension (HD) photodetectors. So far, significant progresses have been made for 2-D material based HD photodetectors to exhibit obviously higher performance than 2-D material photodetectors. The merits of VDW HD junctions in photodetection are introduced in this paper, and the photodetector research achievements of the HD styles including 2D-0D, 2D-1D, 2D-3D, and multi-layer multi-dimension are reviewed. Some insight into the possible challenges and future prospects of 2-D materials based HD-structure photodetectors is attempted.
2024,
48(6):
856-866.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.011
Abstract:
Multi-spectral detection had significant applications in many fields of industry. High-performance broadband photodetectors integrating multi-band responses became one of the important research directions of optical imaging technology. Current research progress of broadband photodetectors was briefly introduced.The prospects of 2-D/3-D mix-dimensional van der Waals (VDW) heterojunctions in the development of broadband photodetectors were elaborated. Some progress of broadband phototransistors based on 2-D transition metal dichalcogenides/3-D group Ⅳ materials VDW heterojunctions by the research group, including traditional NPN-type, PNP-type phototransistors and emerging phototransistors with Schottky junction collectors were reviewed.Ultimately, the applications of these phototransistors were prospected.
Multi-spectral detection had significant applications in many fields of industry. High-performance broadband photodetectors integrating multi-band responses became one of the important research directions of optical imaging technology. Current research progress of broadband photodetectors was briefly introduced.The prospects of 2-D/3-D mix-dimensional van der Waals (VDW) heterojunctions in the development of broadband photodetectors were elaborated. Some progress of broadband phototransistors based on 2-D transition metal dichalcogenides/3-D group Ⅳ materials VDW heterojunctions by the research group, including traditional NPN-type, PNP-type phototransistors and emerging phototransistors with Schottky junction collectors were reviewed.Ultimately, the applications of these phototransistors were prospected.
2024,
48(6):
867-875.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.012
Abstract:
In order to enhance the responsivity, response speed and response spectral range of 2-D MoS2 photodetectors, high-quality multilayer MoS2 nanosheets were prepared by inserting tetrahexyl ammonium chloride(THA+) into bulks MoS2 through an electrochemical workstation and ultrasound-assisted exfoliation process. Thereafter, the MoS2 photodetectors were prepared by the spin-coating the prepared MoS2 nanosheets on the substate. Subsequently, the detector was modified by the Au nanorods (Au NRs) with double plasmon modes to further enhance the interaction between the photo sensing layer and the incident light. Experimental results show that the responsivity of the MoS2/Au NRs photodetector is improved from 2.4×10-3 A/W to 0.484 A/W, and the response time is boosted from 50 ms to 20 ms.In summary, this work not only provides a facile and effective method to expandthe detectable spectral range of the photo detector, but also improve the performance of the photo detector.
In order to enhance the responsivity, response speed and response spectral range of 2-D MoS2 photodetectors, high-quality multilayer MoS2 nanosheets were prepared by inserting tetrahexyl ammonium chloride(THA+) into bulks MoS2 through an electrochemical workstation and ultrasound-assisted exfoliation process. Thereafter, the MoS2 photodetectors were prepared by the spin-coating the prepared MoS2 nanosheets on the substate. Subsequently, the detector was modified by the Au nanorods (Au NRs) with double plasmon modes to further enhance the interaction between the photo sensing layer and the incident light. Experimental results show that the responsivity of the MoS2/Au NRs photodetector is improved from 2.4×10-3 A/W to 0.484 A/W, and the response time is boosted from 50 ms to 20 ms.In summary, this work not only provides a facile and effective method to expandthe detectable spectral range of the photo detector, but also improve the performance of the photo detector.
2024,
48(6):
876-883.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.013
Abstract:
Polariton lasing is a new type of lasing that realizes ultra-low threshold lasing with the coherence of Bose-Einstein condensation(BEC) of exciton-polariton in semiconductors. Unlike conventional 3-D organic and inorganic materials, 2-D transition metal dichalcogenides and 2-D perovskite show great potential in the further development of polariton lasing due to their high exciton binding energies, high oscillator strengths, direct band gaps, van der Waals properties, and valley polarization properties, which are conducive to the realization of strong coupling of exciton and cavity modes and BEC of exciton-polariton. In this review, the principle and progress of polariton lasing in 2-D transition metal chalcogenides and perovskite were mainly focused on, starting with development of strong coupling between exciton and cavity modes. Then, the modulation of the coherence of polariton, the realization of the BEC and polariton lasing was introduced. Finally, an outlook will be given on the future development of polariton lasing in 2-D materials.
Polariton lasing is a new type of lasing that realizes ultra-low threshold lasing with the coherence of Bose-Einstein condensation(BEC) of exciton-polariton in semiconductors. Unlike conventional 3-D organic and inorganic materials, 2-D transition metal dichalcogenides and 2-D perovskite show great potential in the further development of polariton lasing due to their high exciton binding energies, high oscillator strengths, direct band gaps, van der Waals properties, and valley polarization properties, which are conducive to the realization of strong coupling of exciton and cavity modes and BEC of exciton-polariton. In this review, the principle and progress of polariton lasing in 2-D transition metal chalcogenides and perovskite were mainly focused on, starting with development of strong coupling between exciton and cavity modes. Then, the modulation of the coherence of polariton, the realization of the BEC and polariton lasing was introduced. Finally, an outlook will be given on the future development of polariton lasing in 2-D materials.
2024,
48(6):
884-890.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.014
Abstract:
In order to meet the requirements of new renewable energy technologies for electrode materials with appropriate structural, electronic, and mechanical properties, first principles calculations were used to study the electrochemical properties and potential applications of B2S3 semiconductor optoelectronic materials with dynamic, mechanical, and thermal stability. The research results indicate that as an anode material, B2S3 monolayer has suitable storage capacity (Li: 227.2 mAh/g; Na: 340.8 mAh/g), ultra-low diffusion barrier (Li: 0.23 eV; Na: 0.14 eV), and low average open circuit voltage (Li: 0.515 eV; Na: 0.162 eV). It has relatively small lattice changes (Li: 2.5%; Na: 2.1%) during charge and discharge processes. Under different concentrations of lithium/sodium ion adsorption, the metal properties of B2S3 monolayer remain unchanged, exhibiting good conductivity and battery stability. This study indicates that B2S3 semiconductor optoelectronic material is an attractive anode candidate material for lithium/sodium ion batteries. The excellent properties of B2S3 monolayer can further explore its application as an anode material for lithium/sodium ion batteries.
In order to meet the requirements of new renewable energy technologies for electrode materials with appropriate structural, electronic, and mechanical properties, first principles calculations were used to study the electrochemical properties and potential applications of B2S3 semiconductor optoelectronic materials with dynamic, mechanical, and thermal stability. The research results indicate that as an anode material, B2S3 monolayer has suitable storage capacity (Li: 227.2 mAh/g; Na: 340.8 mAh/g), ultra-low diffusion barrier (Li: 0.23 eV; Na: 0.14 eV), and low average open circuit voltage (Li: 0.515 eV; Na: 0.162 eV). It has relatively small lattice changes (Li: 2.5%; Na: 2.1%) during charge and discharge processes. Under different concentrations of lithium/sodium ion adsorption, the metal properties of B2S3 monolayer remain unchanged, exhibiting good conductivity and battery stability. This study indicates that B2S3 semiconductor optoelectronic material is an attractive anode candidate material for lithium/sodium ion batteries. The excellent properties of B2S3 monolayer can further explore its application as an anode material for lithium/sodium ion batteries.
2024,
48(6):
891-899.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.015
Abstract:
In order to prepare lightweight high entropy alloy (LHEA) with suitable microstructure and excellent properties, Ti3V2NbAlxNiy LHEA with different Al and Ni ratios were prepared on TC4 substrate using laser cladding technology. Its microstructure, friction, and wear properties were studied, and the effect of adding a small amount of MoB ceramic particles on its microstructure and properties was discussed. The results show that the phases of Ti3V2NbAl0.5Ni0.5, Ti3V2NbAl0.5 and Ti3V2NbNi0.5 coatings are composed of a single body-centered cubic crystal(BCC), while the second phase A15 is formed in Ti3V2NbAl0.5Ni0.5/MoB coatings. Compared with the hardness of the matrix, the hardness of four coatings has been improved. The wear forms of four coatings are mainly adhesive wear, with adhesive layer and a small amount of oxide layer distributed in the wear marks, and furrow characteristics caused by slight abrasive wear are also observed in the wear marks. Compared with the matrix, the wear rate of Ti3V2NbAl0.5Ni0.5/MoB coating is greatly reduced, and the wear rate of Ti3V2NbAl0.5Ni0.5/MoB coating is reduced by 51.1%. The LHEA in this paper has good wear resistance and can be used as a protective coating for TC4 parts in aerospace, national defense equipment manufacturing and other fields.
In order to prepare lightweight high entropy alloy (LHEA) with suitable microstructure and excellent properties, Ti3V2NbAlxNiy LHEA with different Al and Ni ratios were prepared on TC4 substrate using laser cladding technology. Its microstructure, friction, and wear properties were studied, and the effect of adding a small amount of MoB ceramic particles on its microstructure and properties was discussed. The results show that the phases of Ti3V2NbAl0.5Ni0.5, Ti3V2NbAl0.5 and Ti3V2NbNi0.5 coatings are composed of a single body-centered cubic crystal(BCC), while the second phase A15 is formed in Ti3V2NbAl0.5Ni0.5/MoB coatings. Compared with the hardness of the matrix, the hardness of four coatings has been improved. The wear forms of four coatings are mainly adhesive wear, with adhesive layer and a small amount of oxide layer distributed in the wear marks, and furrow characteristics caused by slight abrasive wear are also observed in the wear marks. Compared with the matrix, the wear rate of Ti3V2NbAl0.5Ni0.5/MoB coating is greatly reduced, and the wear rate of Ti3V2NbAl0.5Ni0.5/MoB coating is reduced by 51.1%. The LHEA in this paper has good wear resistance and can be used as a protective coating for TC4 parts in aerospace, national defense equipment manufacturing and other fields.
2024,
48(6):
900-905.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.016
Abstract:
Aiming at the characteristics of low relative load capacity and small volume capacity of helicopter platform, and to achieve the purpose of efficient pumping of airborne pulse laser media, an integrated structural design method was adopted to design an efficient pulse power supply system that provides pumping energy for pulse xenon lamps of podded lamp-pumping solid-state laser. Theoretical analysis and experimental verification were conducted on the discharge characteristics and device parameters of xenon lamps, and the key device parameters of discharge main circuit of xenon lamp were obtained. A principle prototype was trial-produced, and joint debugging experiments were conducted. The results show that the actual test data are basically consistent with the theoretical data, and the discharge loop parameters of the pulse power supply system are designed reasonably. The total mass of the power supply system is about 48 kg, the capacitor charging time is 3.76 s, the peak discharge-current of xenon lamp is 3.6 kA, and the pulse width is 1.06 ms, respectively. After adopting the integrated structural design method, the volume and weight of the pulse power supply system can meet the requirements of the airborne platform, verifying the feasibility of the key technology.
Aiming at the characteristics of low relative load capacity and small volume capacity of helicopter platform, and to achieve the purpose of efficient pumping of airborne pulse laser media, an integrated structural design method was adopted to design an efficient pulse power supply system that provides pumping energy for pulse xenon lamps of podded lamp-pumping solid-state laser. Theoretical analysis and experimental verification were conducted on the discharge characteristics and device parameters of xenon lamps, and the key device parameters of discharge main circuit of xenon lamp were obtained. A principle prototype was trial-produced, and joint debugging experiments were conducted. The results show that the actual test data are basically consistent with the theoretical data, and the discharge loop parameters of the pulse power supply system are designed reasonably. The total mass of the power supply system is about 48 kg, the capacitor charging time is 3.76 s, the peak discharge-current of xenon lamp is 3.6 kA, and the pulse width is 1.06 ms, respectively. After adopting the integrated structural design method, the volume and weight of the pulse power supply system can meet the requirements of the airborne platform, verifying the feasibility of the key technology.
2024,
48(6):
906-912.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.017
Abstract:
In order to solve the problems of high processing difficulty and limited spectral application range of specific spectra device in traditional quadriwave lateral shearing interferometry system, dividing incident light beam into four beams of lateral shearing coherent wavelets was proposed by using a spatial light modulator instead of a spectro grating. The diffraction efficiency of wavelets was adjusted flexibly by adjusting the refractive index of grating to adapt to the illumination light source, and the optical path difference distribution reflecting the height information and refractive index of the sample was reconstructed according to the interference effect between two wavelets, so as to realize accurate measurement of surface topography in a wide spectral and large dimensions range. In this study, the effect of incident light wavelength on the reconstruction accuracy of optical path difference was investigated by combining the Fourier transform method, and a wide spectrum quadriwave lateral shearing interferometry system from the visible to near infrared was built using a spatial light modulator. The results show that the system measured the etching depth of a standard quartz sample at 209.39 nm±1.72 nm, which is basically consistent with its nominal value of 210.83 nm±2.39 nm and the measurement value of 212.92 nm±1.35 nm by white light interferometer, which verifies the effectiveness of the surface topography measurement method proposed. This study can provide a theoretical reference for the extended application of quadriwave lateral shearing interferometry in the field of surface topography measurement.
In order to solve the problems of high processing difficulty and limited spectral application range of specific spectra device in traditional quadriwave lateral shearing interferometry system, dividing incident light beam into four beams of lateral shearing coherent wavelets was proposed by using a spatial light modulator instead of a spectro grating. The diffraction efficiency of wavelets was adjusted flexibly by adjusting the refractive index of grating to adapt to the illumination light source, and the optical path difference distribution reflecting the height information and refractive index of the sample was reconstructed according to the interference effect between two wavelets, so as to realize accurate measurement of surface topography in a wide spectral and large dimensions range. In this study, the effect of incident light wavelength on the reconstruction accuracy of optical path difference was investigated by combining the Fourier transform method, and a wide spectrum quadriwave lateral shearing interferometry system from the visible to near infrared was built using a spatial light modulator. The results show that the system measured the etching depth of a standard quartz sample at 209.39 nm±1.72 nm, which is basically consistent with its nominal value of 210.83 nm±2.39 nm and the measurement value of 212.92 nm±1.35 nm by white light interferometer, which verifies the effectiveness of the surface topography measurement method proposed. This study can provide a theoretical reference for the extended application of quadriwave lateral shearing interferometry in the field of surface topography measurement.
2024,
48(6):
913-921.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.018
Abstract:
In order to rapidly optimize the ultrasonic-assisted underwater nanosecond laser cutting process, the impact of cavitation bubble dynamics characteristics (CBDC) on the process outcomes was analyzed. And theoretical analysis and experimental validation were carried out using numerical simulation analysis, orthogonal experiments, and high-speed imaging methods. Optimal parameters for the ultrasonic-assisted underwater laser cutting process were obtained, and the CBDC was confirmed to be the primary factor affecting the cutting process. The results showe that as the interference of cavitation bubbles with the laser beam increases, the cutting depth decreases while the cutting speed increases. As the depth-to-width ratio of the groove increases, the pulsating shock from cavitation bubbles exerte greater equivalent stress on the groove bottom. The maximum depth-to-width ratio of approximately is 1.71 achieved when ultrasonic power Pu=65 W, water layer thickness hw=1 mm, laser pulse frequency fq=20 kHz, and laser scanning speed v=1 mm/s, respectively. Under these conditions, the groove width is approximately 99.88 μm, the groove depth is approximately 170.18 μm, the size of the heat-affected zone is approximately 31.71 μm, and the microcrack length is approximately 33.42 μm. At this time, the cavitation bubble cycle is shorter (approximately 100 μs~160 μs). This research can provide valuable insights for optimizing the parameters of multi-field underwater laser composite processing.
In order to rapidly optimize the ultrasonic-assisted underwater nanosecond laser cutting process, the impact of cavitation bubble dynamics characteristics (CBDC) on the process outcomes was analyzed. And theoretical analysis and experimental validation were carried out using numerical simulation analysis, orthogonal experiments, and high-speed imaging methods. Optimal parameters for the ultrasonic-assisted underwater laser cutting process were obtained, and the CBDC was confirmed to be the primary factor affecting the cutting process. The results showe that as the interference of cavitation bubbles with the laser beam increases, the cutting depth decreases while the cutting speed increases. As the depth-to-width ratio of the groove increases, the pulsating shock from cavitation bubbles exerte greater equivalent stress on the groove bottom. The maximum depth-to-width ratio of approximately is 1.71 achieved when ultrasonic power Pu=65 W, water layer thickness hw=1 mm, laser pulse frequency fq=20 kHz, and laser scanning speed v=1 mm/s, respectively. Under these conditions, the groove width is approximately 99.88 μm, the groove depth is approximately 170.18 μm, the size of the heat-affected zone is approximately 31.71 μm, and the microcrack length is approximately 33.42 μm. At this time, the cavitation bubble cycle is shorter (approximately 100 μs~160 μs). This research can provide valuable insights for optimizing the parameters of multi-field underwater laser composite processing.
2024,
48(6):
922-930.
doi: 10.7510/jgjs.issn.1001-3806.2024.06.019
Abstract:
To solve the problem of high misidentification rate, high missed detection rate, low algorithm execution efficiency, and poor model generalization ability in the recognition of volatile organic compound (VOC) leakage area of infrared gas imager, a VOC leakage area recognition method based on motion feature enhancement was proposed. The video stability threshold was determined by using the statistical method of projection change rate of video sequence, and the moving background and moving foreground were extracted under stable state. Optimized linear stretching was used to perform feature enhancement and outlier filtering on the moving foreground. The motion foreground was fused with the original frame, and VOC leakage area identification was performed using the target detection algorithm. Through the method of model pre-training and transfer learning, the smoke dataset and a small amount of VOC leakage dataset were used to train the recognition model, and the model was transferred to the RK3588S embedded development board for execution efficiency test. Experimental results show that the mean average precision of the proposed algorithm is 0.88 when the intersection over union ratio is 0.5, and the mean average precision is 0.51 when the intersection over union ratio ranges from 0.5 to 0.95. The average recognition time of a single frame is 49 ms, which has high recognition accuracy and recognition efficiency, and can meet the requirements of real-time monitoring. The algorithm in this article can maintain stable model performance and has certain anti-interference capabilities providing some reference for VOC leak identification.
To solve the problem of high misidentification rate, high missed detection rate, low algorithm execution efficiency, and poor model generalization ability in the recognition of volatile organic compound (VOC) leakage area of infrared gas imager, a VOC leakage area recognition method based on motion feature enhancement was proposed. The video stability threshold was determined by using the statistical method of projection change rate of video sequence, and the moving background and moving foreground were extracted under stable state. Optimized linear stretching was used to perform feature enhancement and outlier filtering on the moving foreground. The motion foreground was fused with the original frame, and VOC leakage area identification was performed using the target detection algorithm. Through the method of model pre-training and transfer learning, the smoke dataset and a small amount of VOC leakage dataset were used to train the recognition model, and the model was transferred to the RK3588S embedded development board for execution efficiency test. Experimental results show that the mean average precision of the proposed algorithm is 0.88 when the intersection over union ratio is 0.5, and the mean average precision is 0.51 when the intersection over union ratio ranges from 0.5 to 0.95. The average recognition time of a single frame is 49 ms, which has high recognition accuracy and recognition efficiency, and can meet the requirements of real-time monitoring. The algorithm in this article can maintain stable model performance and has certain anti-interference capabilities providing some reference for VOC leak identification.
