A Q-switched noise-like pulse operation was observed in a nonlinear polarization evolution based thulium-doped fiber laser. This novel phenomena formed in a noise like background. When the pump power was properly controlled and the polarization controller was carefully adjusted, a noise like mode locked pulse was modulated by a Q-switched pulse envelope, which resulted in the Q-switched noise-like pulse formation. In a single pulse envelope, there exist many mode locked pulses that have fundamental repetition rate which is corresponded to the cavity period. When the pump power was carefully increased from 760 mW to 1000 mW, the repetition rate of the adjacent pulse envelope can increased from 34 to 41.1 kHz, and then intra-cavity pulse energy of a envelope reached about 609 nJ. This phenomenon was first observed in thulium-doped fiber laser. It will add experimental basis for studying of the pulse dynamics in fiber lasers.
{"title":"Q-switched Noise-Like Pulse in a Tm-doped Fiber Laser","authors":"Jingmin Liu, Xingliang Li, Shumin Zhang, Chaoran Wang, Liangliang Chen, Zihao Guo, Lisha Liu, Yaxing Xin, Zhenjun Yang","doi":"10.1109/OGC.2019.8925286","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925286","url":null,"abstract":"A Q-switched noise-like pulse operation was observed in a nonlinear polarization evolution based thulium-doped fiber laser. This novel phenomena formed in a noise like background. When the pump power was properly controlled and the polarization controller was carefully adjusted, a noise like mode locked pulse was modulated by a Q-switched pulse envelope, which resulted in the Q-switched noise-like pulse formation. In a single pulse envelope, there exist many mode locked pulses that have fundamental repetition rate which is corresponded to the cavity period. When the pump power was carefully increased from 760 mW to 1000 mW, the repetition rate of the adjacent pulse envelope can increased from 34 to 41.1 kHz, and then intra-cavity pulse energy of a envelope reached about 609 nJ. This phenomenon was first observed in thulium-doped fiber laser. It will add experimental basis for studying of the pulse dynamics in fiber lasers.","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133406627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/OGC.2019.8925258
Jun Pan, Xiaoyu Sun, Jijun Feng, H. Zeng
A single mode tapered fiber is fabricated for the measurement of DNA molecule with monitoring the surrounding refractive index changes. The slimmest dimension of the fiber is roughly $mathbf{8 mu m}$. Refractive index change was given an expression by observing the shifting of transmission spectrum dip with a sensitivity about 1342 nm/RIU. Such a sensor owns the superiorities of easy carrying, anti-electromagnetic interference and short manufacturing cycle, which would have a wide application prospect.
制作了一种单模锥形光纤，用于DNA分子的测量，并监测其周围折射率的变化。纤维最细的尺寸大约是$mathbf{8 mu m}$。在1342 nm/RIU的灵敏度下，通过观察透射光谱倾角的变化，给出了折射率变化的表达式。该传感器具有携带方便、抗电磁干扰、制造周期短等优点，具有广阔的应用前景。
{"title":"Tapered Fiber Based Infrared DNA Molecule Sensor","authors":"Jun Pan, Xiaoyu Sun, Jijun Feng, H. Zeng","doi":"10.1109/OGC.2019.8925258","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925258","url":null,"abstract":"A single mode tapered fiber is fabricated for the measurement of DNA molecule with monitoring the surrounding refractive index changes. The slimmest dimension of the fiber is roughly $mathbf{8 mu m}$. Refractive index change was given an expression by observing the shifting of transmission spectrum dip with a sensitivity about 1342 nm/RIU. Such a sensor owns the superiorities of easy carrying, anti-electromagnetic interference and short manufacturing cycle, which would have a wide application prospect.","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126132078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/OGC.2019.8925238
Qiang Sun, Mingming Dong, Yang Zhou
P-Cycle protection technology is an important technology in optical network protection. This paper proposes a new P-Cycle construction algorithm ERPA (Extended cycle Restriction Based P-Cycle Construction Algorithm), which is based on the variance, mean and redundancy of unprotected working capacity on all candidate cycles. In the process of cycle expansion, the algorithm chooses the extended candidate cycle whose variance, mean and redundancy satisfy the conditions as the final candidate cycle of the current round, which can guarantee the quality of the extended cycle and limit the number of P-Cycle cycles that complete the protection; When the values of unprotected-links(UPL), the redundancy, mean and the parameter n satisfy the stop condition, the cycle expansion is stopped, so that the number of cycles and the cycle length can be effectively balanced. In the simulation process, the ERPA algorithm is simulated by using the COST293 European Optical Network (EON) topology model, and the performance under different n values is compared and analyzed. The simulation results show that ERPA algorithm needs fewer cycles, has higher protection capacity efficiency and lower total time consumption under the same resource and work capacity, which makes the proposed algorithm more feasible and effective.
p周期保护技术是光网络保护中的一项重要技术。本文提出了一种新的基于扩展循环约束的p循环构造算法ERPA (Extended cycle Restriction Based P-Cycle construction algorithm)，该算法基于所有候选循环上无保护工作容量的方差、均值和冗余。在循环展开过程中，算法选择方差、均值和冗余满足条件的扩展候选循环作为本轮的最终候选循环，既保证了扩展周期的质量，又限制了完成保护的P-Cycle循环的数量;当UPL (unprotected-links)、冗余、平均值和参数n满足停止条件时，停止循环扩展，使循环数和周期长度得到有效平衡。在仿真过程中，采用COST293欧洲光网络(EON)拓扑模型对ERPA算法进行了仿真，并对不同n值下的性能进行了比较分析。仿真结果表明，在相同的资源和工作容量下，ERPA算法所需的周期更少，具有更高的保护容量效率和更低的总耗时，使所提算法更加可行和有效。
{"title":"Study of Extended Cycle Restriction Based P-Cycle Construction Algorithm","authors":"Qiang Sun, Mingming Dong, Yang Zhou","doi":"10.1109/OGC.2019.8925238","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925238","url":null,"abstract":"P-Cycle protection technology is an important technology in optical network protection. This paper proposes a new P-Cycle construction algorithm ERPA (Extended cycle Restriction Based P-Cycle Construction Algorithm), which is based on the variance, mean and redundancy of unprotected working capacity on all candidate cycles. In the process of cycle expansion, the algorithm chooses the extended candidate cycle whose variance, mean and redundancy satisfy the conditions as the final candidate cycle of the current round, which can guarantee the quality of the extended cycle and limit the number of P-Cycle cycles that complete the protection; When the values of unprotected-links(UPL), the redundancy, mean and the parameter n satisfy the stop condition, the cycle expansion is stopped, so that the number of cycles and the cycle length can be effectively balanced. In the simulation process, the ERPA algorithm is simulated by using the COST293 European Optical Network (EON) topology model, and the performance under different n values is compared and analyzed. The simulation results show that ERPA algorithm needs fewer cycles, has higher protection capacity efficiency and lower total time consumption under the same resource and work capacity, which makes the proposed algorithm more feasible and effective.","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129475941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a near-infrared array receiver consisting of two 16-element linear-arrays InGaAs reach-through avalanche photodiodes and readout circuit assembled by system-level integrated package was developed for 3D realtime imaging. The readout circuit includes 32 transimpedance amplifiers, double-threshold comparators and time-to-digital converters (TDC). With transimpedance amplifier based on closed-loop structure of inverter-like amplifier circuit, and post-stage differential output amplifier, the readout circuit can achieve high gain, large bandwidth and low noise. The double threshold comparator was used to solve walking error. With two-step architecture combining 8-bit coarse counting and 6-bit fine counting, the dynamic range of the receiver is increased by coarse counting while its resolution is improved by combining fine counting. When the system emits a laser pulse, the receiver starts timing and converts the echo signal to a voltage signal. When a stop timing signal is generated, the system quantifies the time of flight to 14-bit digital signal. The developed receiver demonstrates the pulse responsivity of $mathbf{5.4}times 10^{5} mathbf{V}/mathbf{W}$, the 3dB bandwidth of 142.9 MHz, the minimum detectable optical power of about 26.7 nW $(mathbf{SNR}=10)$, and the time resolution of 200 ps. When the receiver is applied to a lidar system, where a 1550 nm semiconductor laser illuminates the target scene with pulse width shorter than 10 ns and repetition frequency more than 20 kHz, combining timing control with software algorithm, we get a clear environmental 3D image in real time.
{"title":"Near-Infrared Array Receiver for Real-Time 3D Imaging Application","authors":"Yun-xiu Yang, Jianbo Gao, Haizhi Song, Changdong Guo, Shijie Deng, Qian Dai, Haihua Huang, Xianguo Kou, Xiaolong Lu, Fei Yuan, Li Jing","doi":"10.1109/OGC.2019.8925085","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925085","url":null,"abstract":"In this paper, a near-infrared array receiver consisting of two 16-element linear-arrays InGaAs reach-through avalanche photodiodes and readout circuit assembled by system-level integrated package was developed for 3D realtime imaging. The readout circuit includes 32 transimpedance amplifiers, double-threshold comparators and time-to-digital converters (TDC). With transimpedance amplifier based on closed-loop structure of inverter-like amplifier circuit, and post-stage differential output amplifier, the readout circuit can achieve high gain, large bandwidth and low noise. The double threshold comparator was used to solve walking error. With two-step architecture combining 8-bit coarse counting and 6-bit fine counting, the dynamic range of the receiver is increased by coarse counting while its resolution is improved by combining fine counting. When the system emits a laser pulse, the receiver starts timing and converts the echo signal to a voltage signal. When a stop timing signal is generated, the system quantifies the time of flight to 14-bit digital signal. The developed receiver demonstrates the pulse responsivity of $mathbf{5.4}times 10^{5} mathbf{V}/mathbf{W}$, the 3dB bandwidth of 142.9 MHz, the minimum detectable optical power of about 26.7 nW $(mathbf{SNR}=10)$, and the time resolution of 200 ps. When the receiver is applied to a lidar system, where a 1550 nm semiconductor laser illuminates the target scene with pulse width shorter than 10 ns and repetition frequency more than 20 kHz, combining timing control with software algorithm, we get a clear environmental 3D image in real time.","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131389739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/OGC.2019.8925087
Y. Qiu, Yehua Xie, Weimin Wang, Wenbin Liu, L. Kuang, Xue Bai, M. Hu, J. Ho
We report the design, fabrication and characterization of ultra-high-power and high-efficiency 905-nm pulsed lasers with four epitaxially stacked emitters connected by tunnel junctions for LiDAR application. The P-side-up submounted multimode lasers produce as high as 150 W at the current of 35 A and environmental temperature of 25°C. At the output power of 111.5 W, the Wall-Plug Efficiency and slope efficiency reach 41.4% and 4.66 W/A, respectively. The measurement shows $mathbf{284-mu m}$ beam width and 12.6-degree horizontal far-field angle (95% power enclosure), indicating high brightness for this device, making it well - suited for long-distance and high-spatial-resolution range finding.
{"title":"Ultra-High-Power and High-Efficiency 905nm Pulsed Laser for LiDAR","authors":"Y. Qiu, Yehua Xie, Weimin Wang, Wenbin Liu, L. Kuang, Xue Bai, M. Hu, J. Ho","doi":"10.1109/OGC.2019.8925087","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925087","url":null,"abstract":"We report the design, fabrication and characterization of ultra-high-power and high-efficiency 905-nm pulsed lasers with four epitaxially stacked emitters connected by tunnel junctions for LiDAR application. The P-side-up submounted multimode lasers produce as high as 150 W at the current of 35 A and environmental temperature of 25°C. At the output power of 111.5 W, the Wall-Plug Efficiency and slope efficiency reach 41.4% and 4.66 W/A, respectively. The measurement shows $mathbf{284-mu m}$ beam width and 12.6-degree horizontal far-field angle (95% power enclosure), indicating high brightness for this device, making it well - suited for long-distance and high-spatial-resolution range finding.","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"185 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114166104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/OGC.2019.8925285
Fei Yuan, Xiaolong Lu, Li Jing, Yun-xiu Yang, Fanlin Kong, Shijie Deng, Changdong Guo, Haizhi Song
With high sensitivity at single photon level, Geiger-Mode (GM) avalanche photodiodes (APD) are widely used in spectrum measurement, 3D imaging, astronomical observation, biomedical and other fields. In this paper, a high-speed photon counting system is proposed with an active quench and reset integrated circuit (AQR-IC) that drives a near infrared InGaAs GM-APD. The avalanche current is converted into voltage signal by utilizing parasitic capacitance of APD and circuit's input port. Multi-stage inverters detect the induced voltage, and generate an output TTL pulse indicating occurrence of avalanche event. At the same time, the active quench circuit is introduced to stop avalanche quickly. Then the active reset circuit makes APD working in Geiger mode after a programmable delay time which could be set by field programmable gate array(FPGA). The adjustable dead time enormously improve the flexibility of photon counting system applications. The proposed AQR-IC was fabricated in SMIC $mathbf{0.18 mu m}$ CMOS process. Applied for InGaAs GM-APD, experimental results show that the circuit is capable of fast quenching and recovering. The system provides adjustable dead time from 64 ns up to $mathbf{163.6 mu s}$ with a setting resolution of 20 ns, corresponding to a maximum counting rate of 15.6 MHz. The system can meet the application requirement of free-running mode detection.
盖革模式雪崩光电二极管(APD)具有单光子水平的高灵敏度，广泛应用于光谱测量、三维成像、天文观测、生物医学等领域。本文提出了一种采用有源猝灭复位集成电路(AQR-IC)驱动近红外InGaAs GM-APD的高速光子计数系统。雪崩电流通过APD的寄生电容和电路的输入端口转换成电压信号。多级逆变器检测感应电压，并产生一个输出TTL脉冲，指示雪崩事件的发生。同时引入有源猝灭电路，实现雪崩快速停止。然后，有源复位电路使APD在经过可编程延迟时间后工作在盖革模式，该延迟时间可由现场可编程门阵列(FPGA)设定。死区时间的可调极大地提高了光子计数系统应用的灵活性。该AQR-IC采用SMIC $mathbf{0.18 mu m}$ CMOS工艺制备。应用于InGaAs GM-APD，实验结果表明该电路具有快速猝灭和恢复的能力。该系统提供从64 ns到$mathbf{163.6 mu s}$的可调死区时间，设置分辨率为20 ns，对应于15.6 MHz的最大计数率。该系统可以满足自由运行模式检测的应用需求。
{"title":"A Novel High-Speed Photon Counting System with Programmed Dead Time","authors":"Fei Yuan, Xiaolong Lu, Li Jing, Yun-xiu Yang, Fanlin Kong, Shijie Deng, Changdong Guo, Haizhi Song","doi":"10.1109/OGC.2019.8925285","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925285","url":null,"abstract":"With high sensitivity at single photon level, Geiger-Mode (GM) avalanche photodiodes (APD) are widely used in spectrum measurement, 3D imaging, astronomical observation, biomedical and other fields. In this paper, a high-speed photon counting system is proposed with an active quench and reset integrated circuit (AQR-IC) that drives a near infrared InGaAs GM-APD. The avalanche current is converted into voltage signal by utilizing parasitic capacitance of APD and circuit's input port. Multi-stage inverters detect the induced voltage, and generate an output TTL pulse indicating occurrence of avalanche event. At the same time, the active quench circuit is introduced to stop avalanche quickly. Then the active reset circuit makes APD working in Geiger mode after a programmable delay time which could be set by field programmable gate array(FPGA). The adjustable dead time enormously improve the flexibility of photon counting system applications. The proposed AQR-IC was fabricated in SMIC $mathbf{0.18 mu m}$ CMOS process. Applied for InGaAs GM-APD, experimental results show that the circuit is capable of fast quenching and recovering. The system provides adjustable dead time from 64 ns up to $mathbf{163.6 mu s}$ with a setting resolution of 20 ns, corresponding to a maximum counting rate of 15.6 MHz. The system can meet the application requirement of free-running mode detection.","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115107601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new category of harmonic mode-locked pattern is reported in passively mode-locked fiber laser (MLFL). The laser base on gold nanorods (GNRs) as a mechanism to trigger mode locking. By adjusting polarization controllers and pumping power, including fundamental mode-locked pulse, condensed soliton phase, soliton rain, harmonic condensed soliton phase have been observed. The harmonics condensed soliton phase were experimentally verified for the first time in the MLFL. The experimental results explained the conditions for the generation of condensed soliton phase and extend the pulse type of harmonic mode-locking (HML).
{"title":"Harmonic Condensed Soliton Phase in a Mode-Locked Fiber Laser","authors":"Liangliang Chen, Xingliang Li, Shumin Zhang, Jingmin Liu, Chaoran Wang, Zihao Guo, Lisha Liu, Yaxing Xin, Zhenjun Yang","doi":"10.1109/OGC.2019.8925148","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925148","url":null,"abstract":"A new category of harmonic mode-locked pattern is reported in passively mode-locked fiber laser (MLFL). The laser base on gold nanorods (GNRs) as a mechanism to trigger mode locking. By adjusting polarization controllers and pumping power, including fundamental mode-locked pulse, condensed soliton phase, soliton rain, harmonic condensed soliton phase have been observed. The harmonics condensed soliton phase were experimentally verified for the first time in the MLFL. The experimental results explained the conditions for the generation of condensed soliton phase and extend the pulse type of harmonic mode-locking (HML).","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"360 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122651553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/OGC.2019.8925287
Chi Hu, Xiaojun Yu, Qianshan Ding, Zeming Fan, Zhaohui Yuan, Juan Wu, Linbo Liu
Chronic kidney disease (CKD) is one of the public health threats around the world, which may cause serious health problems like cardiovascular disease, kidney failure, or even more serious as premature death. Although CKD usually could be managed by general internists, such a way of treatment can be applied only when significant symptoms appear, which is very slow. It has also been reported that CKD could be characterized by means of glomeruli, and classified by the stages of disease severity for early treatment. However, due to lack of reliable method to detect the cellular-level microstructures for disease severity characterization, the diagnosis is troublesome, and thus, the treatments might be delayed while the best treatment time could be missed. For early detection of CKD, it is imperative to develop reliable tools to detect and characterize the disease at an early stage with minimal or noninvasiveness. For this research, the micro-optical coherence tomography $mathbf{(mu OCT)}$ was assessment it feasibility as a cellular-level structure imaging tool in kidney disease diagnosis at an early stage. Specifically, by measuring the number of glomeruli within a volumetric kidney tissue, a new diagnostic criteria is also established. Imaging results of the kidney specimens as compared their corresponding histology show that the cellular-level glomeruli structures could be identified clearly, and as a basic functional unit of kidney, it could be utilized as a reliable parameter to access the severity of the CKD.
{"title":"Cellular-Level Structure Imaging with Micro-optical Coherence Tomography $mathbf{(mu OCT)}$ for Kidney Disease Diagnosis","authors":"Chi Hu, Xiaojun Yu, Qianshan Ding, Zeming Fan, Zhaohui Yuan, Juan Wu, Linbo Liu","doi":"10.1109/OGC.2019.8925287","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925287","url":null,"abstract":"Chronic kidney disease (CKD) is one of the public health threats around the world, which may cause serious health problems like cardiovascular disease, kidney failure, or even more serious as premature death. Although CKD usually could be managed by general internists, such a way of treatment can be applied only when significant symptoms appear, which is very slow. It has also been reported that CKD could be characterized by means of glomeruli, and classified by the stages of disease severity for early treatment. However, due to lack of reliable method to detect the cellular-level microstructures for disease severity characterization, the diagnosis is troublesome, and thus, the treatments might be delayed while the best treatment time could be missed. For early detection of CKD, it is imperative to develop reliable tools to detect and characterize the disease at an early stage with minimal or noninvasiveness. For this research, the micro-optical coherence tomography $mathbf{(mu OCT)}$ was assessment it feasibility as a cellular-level structure imaging tool in kidney disease diagnosis at an early stage. Specifically, by measuring the number of glomeruli within a volumetric kidney tissue, a new diagnostic criteria is also established. Imaging results of the kidney specimens as compared their corresponding histology show that the cellular-level glomeruli structures could be identified clearly, and as a basic functional unit of kidney, it could be utilized as a reliable parameter to access the severity of the CKD.","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121170867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/OGC.2019.8925011
W. Yi, Hui Chen, Yingzhou Wu, Yong Chen, Hongyu Li
In this paper, the 12CrNi2 alloy steel parts were fabricated by laser melting deposition (LMD) using two kinds of deposition strategies, which were single direction scanning(SDS) and cross direction scanning(CDS). The microstructure and fatigue behavior of LMD 12CrNi2 alloy steel samples were investigated. Thy typical microstructure of both deposition strategy were ferrite and can be divided into two zones: remelted zone and non-remelted zone. The non-remelted zone showed typical columnar crystal morphology while the structure of remelted zone was homogenized. Compared with SDS deposition strategy, the microstructure of CDS deposition strategy had shorter columnar grains and finer grains. The relative densities of SDS and CDS deposition strategies were 98.1 and 97.3, respectively, indicating that SDS had lower porosity. The fatigue strength of SDS deposition strategy was higher than that of CDS deposition strategy, which were 320 MPa and 200 MPa. There were more defects in CDS deposition strategy, which accelerated the initiation and propagation of cracks. CDS deposition strategy had longer interlayer interval time, which will reduce the penetration depth of laser, affect the degree of previous layer remelting, and eventually lead to unmelted powder, porosity and other defects in the lap zone.
{"title":"Effect of Deposition Strategy on Fatigue Behavior of Laser Melting Deposition 12CrNi2 Alloy Steel","authors":"W. Yi, Hui Chen, Yingzhou Wu, Yong Chen, Hongyu Li","doi":"10.1109/OGC.2019.8925011","DOIUrl":"https://doi.org/10.1109/OGC.2019.8925011","url":null,"abstract":"In this paper, the 12CrNi2 alloy steel parts were fabricated by laser melting deposition (LMD) using two kinds of deposition strategies, which were single direction scanning(SDS) and cross direction scanning(CDS). The microstructure and fatigue behavior of LMD 12CrNi2 alloy steel samples were investigated. Thy typical microstructure of both deposition strategy were ferrite and can be divided into two zones: remelted zone and non-remelted zone. The non-remelted zone showed typical columnar crystal morphology while the structure of remelted zone was homogenized. Compared with SDS deposition strategy, the microstructure of CDS deposition strategy had shorter columnar grains and finer grains. The relative densities of SDS and CDS deposition strategies were 98.1 and 97.3, respectively, indicating that SDS had lower porosity. The fatigue strength of SDS deposition strategy was higher than that of CDS deposition strategy, which were 320 MPa and 200 MPa. There were more defects in CDS deposition strategy, which accelerated the initiation and propagation of cracks. CDS deposition strategy had longer interlayer interval time, which will reduce the penetration depth of laser, affect the degree of previous layer remelting, and eventually lead to unmelted powder, porosity and other defects in the lap zone.","PeriodicalId":381981,"journal":{"name":"2019 IEEE 4th Optoelectronics Global Conference (OGC)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123244815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/OGC.2019.8925152
Yang Li, Wenliang Xiao, Liyuan Wu, Xiumin Xie, P. Lu, Shumin Wang
The theoretical dark current model of InAs/GaSb type II superlattice (T2SL) p-i-n and nBn photodetectors is presented. The nBn structure was designed to suppress generation-recombination (G-R), surface leakage and tunnel currents. 8 band $mathbf{k}cdot mathbf{p}$ model including the conduction and valence band mixing was applied to calculate the band structure and optical transition of InAs/GaSb T2SL. Theoretical calculations are performed for different doping level of p-i-n and nBn detectors. For p-i-n detector, dark current was studied for different p-contact layer doping and different absorber layer doping. For nBn detector, different contact doping concentration and absorb doping concentration was studied. At low temperature, dark current of p-i-n detector was dominant by generation-recombination and tunnel current, nBn structure can inhibit tunnel and generation-recombination current. At high temperature, the dark current of p-i-n detector and nBn detector have the same order of magnitude and are both dominated by diffusion current. Quantum efficiency and resistance-area product of p-i-n and nBn detectors were also calculated at 120 K, quantum efficiency of p-i-n detector is a bit larger than nBn detector, but dark current and resistance area product of nBn detector are better.
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