Browsing by Author "Lin, Wei"

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An Investigation on 25Gb/s Ultra-Short Cavity Quantum Well Lasers Operated at Elevated Temperatures
(2019-01-01)
Tsai, Yi-Lin
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Chen, Bo-Hong
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Hsu, Shun-Chieh
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Shih, Hsiang-Yun
;
Lu, Po-Yen
A Fabry-Perot quantum well laser with ultra-short cavity is designed and fabricated. The emission wavelength is at 1310nm band which is important for data center applications. The shortest cavity length is 25 mu m, and the laser has mW-class output with low threshold currents (4mA in average). At room temperature, an opened eye diagram with 28Gb/s transmission rate can be observed. Clear 25Gb/s eye patterns from 15 degrees C to 65 degrees C are also demonstrated.
Bipolar Cascade Superluminescent Diodes at the 1.04-mu m Wavelength Regime
(2009-03-01)
Guol, Shi-Hao
;
Wang, Jr-Hung
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Wu, Yu-Huei
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Lin, Wei
;
Yang, Ying-Jay
In this study, we investigate the performance of GaAs-based bipolar cascade superluminescent diodes with different cavity lengths. The device operates around the important bio-optical therapeutic 1.04-mu m wavelength window. The introduction of tunnel junctions tends to minimize the nonuniform carrier distribution between distinct multiple quantum-wells (QWs), which is a problem in conventional SLDs, whose electroluminescent spectra are governed by the center wavelength of QWs near the p-side. Our devices exhibit nice electrical characteristics of low leakage current and overcome the limitation of nonuniform carrier distribution, thereby presenting a promising prospect for the near infrared white-light sources.
High Improvement in Conversion Efficiency of mu c-SiGe Thin-Film Solar Cells with Field-Enhancement Layers
(2012)
Yu, Shu-Hung
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Lin, Wei
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Chen, Yu-Hung
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Chang, Chun-Yen
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電子工程學系及電子研究所
The improved performance for hydrogenated microcrystalline silicon-germanium (mu c-Si1-xGex:H, x similar to 0.1) p-i-n single solar cells with hydrogenated microcrystalline silicon (mu c-Si:H) field-enhancement layers (FELs) is demonstrated for the first time. The fill factor (FF) and conversion efficiency (eta) increase by about 19% and 28% when the thickness of the mu c-Si FEL is increased from 0 to 200 nm, it is attributed to the longer hole life-time and enhanced electric field in the mu c-Si0.9Ge0.1:H layer. Therefore, we can successfully manufacture high-performance mu c-SiGe:H solar cells with the thickness of absorbers smaller than 1 mu m by conducting FELs. Moreover, the simulation tool is used to simulate the current-voltage (J-V) curve, thus we can investigate the carrier transport in the absorber of mu c-Si0.9Ge0.1:H solar cells with different EFLs.
High Speed Directly Modulated Fabry-Perot Lasers With an Ultra-Short Cavity Length
(2020-05-01)
Tsai, Yi-Lin
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Wang, Shou-Wei
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Huang, Huang-Hsiung
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Shih, Hsiang-Yun
;
Lu, Po-Yen
In this study, Fabry-Perot quantum well lasers with shortened cavity designs (25 and 50 mu m) were fabricated. The devices had dry-etched and cleaved facets and exhibited an output power of up to 2.36 mW for a cavity length of 25 mu m; good spectral performance was achieved. Single-optical-mode operation with better than 25dB of side mode suppression ratio can be achieved for the fabricated devices with 25- and 50-mu m cavities. The short-cavity devices also exhibited highspeed modulation at elevated temperatures. Moreover, 25 Gb/s eye diagrams could be obtained at 65oC for the 25 mu m device and 55oC for the 50 mu m device. Due to their small area, ultra-shortcavity Fabry-Perot laser can be suitably used in next-generation light sources for optical communication.
High-Speed and Duo-Mode 850 nm VCSELs for 47 Gbps Optical Interconnect over 1 km OM4 Fiber
(2015)
Lu, I-Cheng
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Wei, Chia-Chien
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Chen, Hsing-Yu
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Chen, Kuan-Zhou
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Huang, Cheng-Hsiang
Novel duo-mode 850nm VCSELs with short (lambda/2) cavity, oxide-relief and Zn-diffusion apertures are demonstrated to balance the trade-off of speed and reaching bottleneck of VCSELs. Extremely-high data rate (47-Gbps) over 1005m OM4-fiber transmission is reported.
Molecular mechanism studies of mammalian sterile20-like protein kinase 3 in mitochondrial dynamics
(2014-04-01)
Lin, Wei
;
Yuan, Chiun-Jye
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生物科技學系
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Department of Biological Science and Technology
Optimal Floating Gate Potential for Extending Data Retention of Post-Baking Method in Sub-20 nm Triple Level per Cell NAND Flash Memory
(2016-07)
Hsu, Yu-Cheng
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Lin, Wei
;
Chang, Chun-Yen
;
電機學院
;
電子工程學系及電子研究所
A post-baking method with an optimized data pattern is developed to eliminate the program/erase (PE) cycle-induced damage of sub-20 nm NAND Flash memory and to improve its reliability. The electric field of the tunneling oxide (E-ox)-dependent oxide recovery is discussed in detail. The experimental results reveal that additional traps in the tunneling oxide are induced by the E-ox during the baking process via an electron-phonon interaction and the effectiveness of oxide recovery is reduced by the generation of these additional traps. Hence, the additional traps degrade the read margin and retention ability. Therefore, an optimized data pattern is produced to minimize E-ox and reduce the number of additional traps formed during the post-baking process. When the optimized data pattern is utilized in post-baking, the endurance of the sub-20 nm three-level-per-cell (TLC) NAND Flash memory is quadruple improved under one year retention condition.
Strong Enhancements in Static/Dynamic Performances of High-Speed 850 nm Vertical-Cavity Surface-Emitting Lasers with P-type delta-Doping in Highly Strained Active Layers
(2016)
Chi, Kai-Lun
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Chen, Xin-Nan
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Yen, Jia-Liang
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Lin, Wei
;
Chiu, Shi-Wei
By using p-type modulation doping in the highly strained MQWs of high-speed 850 nm VCSELs, significant enhancements in speed, slope efficiency, and maximum power have been simultaneously achieved as compared to those of un-doped references
Superior Data Retention for Sub-20 nm Triple Level Per Cell NAND Flash Memory by Using a Novel Data Programming Method
(2016-07)
Lin, Wei
;
Chang, Chun-Yen
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This work presents a novel data programming method for sub-20 nm triple level per cell (TLC) NAND Flash memory. The proposed method improves data retention ability and reduces the data failure rate of Embedded Multi Media Card (eMMC) during the high temperature reflow of surface mount technology (SMT). More than owing to the high temperature stress, the failure is closely related to the data pattern of the adjacent cell array. The proposed data programming method generates an optimized dummy data pattern based on the data of the last data word line (WL) and, then, programs the optimized dummy data pattern to the word line next to the data edge one to suppress the abrupt electrical potential energy drops caused by the erase data. The graded electrical potential energy can thus reduce the electric field and electron tunneling probability. Furthermore, the row bit error rate (RBER) with the high temperature stress of the last data word line can be reduced 85% by using the novel data programming method. This work also attempts to identify the root cause of the temperature and adjacent data pattern dependent retention by measuring and performing statistical analysis of a sub-20 nm TLC NAND Flash memory chip. 3D numerical simulation with comprehensive quantum tunneling models is also conducted to facilitate the theoretical analysis. Statistical and numerical analysis results indicate that a severe threshold voltage (Vth) shift of the memory cell occurs when the adjacent floating gate (FG) has both high and low Vth states. Above results demonstrate the feasibility of the proposed data programming method in generating the optimized dummy data pattern.
Very High Bit-Rate Distance Product Using High-Power Single-Mode 850-nm VCSEL With Discrete Multitone Modulation Formats Through OM4 Multimode Fiber
(2015-11-01)
Lu, I-Cheng
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Wei, Chia-Chien
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Chen, Hsing-Yu
;
Chen, Kuan-Zhou
;
Huang, Cheng-Hsiang
In order to investigate the tradeoff between optical spectral width and modulation speed of 850-nm Zn-diffusion vertical-cavity surface-emitting laser (VCSEL) and its influence on the performance of discrete multitone (DMT) modulation, two kinds of high-speed VCSEL structures with different cavity lengths (lambda/2 and 3 lambda/2) are studied. By shortening the cavity length to lambda/2, allocating the oxide layer in the standing-wave peak, and performing a Zn-diffusion aperture in our VCSEL structure, stable dual mode in the output optical spectra across the full range of bias currents with good high-speed performance (similar to 16-GHz bandwidth) can be achieved. Compared with its multimode reference, it shows far less roll-off with regard to the maximum data rate versus transmission distance over OM4 multimode fibers under forward error correction (FEC) threshold (BER < 3.8 x 10(-3)). On the other hand, for the 3 lambda/2 VCSEL structure, by using the same Zn-diffusion conditions as those of dual-mode counterpart, highly single-mode operation (side-mode suppression ratio > 35 dB) with high available power can be achieved over the full range of bias currents. Although such device shows a smaller 3-dB electrical-to-optical bandwidth (12 versus 16 GHz) than that of the dual-mode one, it exhibits a superior transmission performance by use of DMT modulation format. A record high bit-rate distance product (107.6 Gb/s.km) at nearly 50-Gb/s transmission under FEC threshold (BER < 3.8 x 10(-3)) through 2.2-km OM4 fibers has been successfully demonstrated by the use of single-mode VCSEL with optimized structures. In addition, error-free (BER< 1 x 10(-12)) transmission at 20.3 Gb/s with bit-rate distance product of 44.66 Gb/s.km has also been demonstrated.