Browsing by Issue Date, starting with "2014-06-02"

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A large bistable negative lens by integrating a polarization switch with a passively anisotropic focusing element
(2014-06-02)
Chen, Hung-Shan
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Lin, Yi-Hsin
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Srivastava, Abhishek Kumar
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Chigrinov, Vladimir Grigorievich
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Chang, Chia-Ming
A bistable negative lens with a large aperture size (similar to 10mm) by integrating a polarization switch of ferroelectric liquid crystals (FLCs) with a passively anisotropic focusing element is demonstrated. The proposed lens not only exhibits electrically tunable bistability but also fast response time of sub-milliseconds. The tunable lens power is from 0 to -1.74 Diopters. The electro-optical properties and imaging performances are demonstrated. The impact of this study is to provide a solution of electrically bistable liquid crystal lenses for the applications of portable devices, wearable devices and colored ophthalmic lenses. (C) 2014 Optical Society of America
Tunable microwave generation of a monolithic dual-wavelength distributed feedback laser
(2014-06-02)
Lo, Yen-Hua
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Wu, Yu-Chang
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Hsu, Shun-Chieh
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Hwang, Yi-Chia
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Chen, Bai-Ci
The dynamic behavior of a monolithic dual-wavelength distributed feedback laser was fully investigated and mapped. The combination of different driving currents for master and slave lasers can generate a wide range of different operational modes, from single mode, period 1 to chaos. Both the optical and microwave spectrum were recorded and analyzed. The detected single mode signal can continuously cover from 15GHz to 50GHz, limited by photodetector bandwidth. The measured optical four-wave-mixing pattern indicates that a 70GHz signal can be generated by this device. By applying rate equation analysis, the important laser parameters can be extracted from the spectrum. The extracted relaxation resonant frequency is found to be 8.96GHz. With the full operational map at hand, the suitable current combination can be applied to the device for proper applications. (C) 2014 Optical Society of America
A scalable and continuous-upgradable optical wireless and wired convergent access network
(2014-06-02)
Sung, J. Y.
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Cheng, K. T.
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Chow, C. W.
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Yeh, C. H.
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Pan, C. -L.
In this work, a scalable and continuous upgradable convergent optical access network is proposed. By using a multi-wavelength coherent comb source and a programmable waveshaper at the central office (CO), optical millimeter-wave (mm-wave) signals of different frequencies (from baseband to > 100 GHz) can be generated. Hence, it provides a scalable and continuous upgradable solution for end-user who needs 60 GHz wireless services now and > 100 GHz wireless services in the future. During the upgrade, user only needs to upgrade their optical networking unit (ONU). A programmable waveshaper is used to select the suitable optical tones with wavelength separation equals to the desired mm-wave frequency; while the CO remains intact. The centralized characteristics of the proposed system can easily add any new service and end-user. The centralized control of the wavelength makes the system more stable. Wired data rate of 17.45 Gb/s and w-band wireless data rate up to 3.36 Gb/s were demonstrated after transmission over 40 km of single-mode fiber (SMF). (C) 2014 Optical Society of America
Passive mode locking of ytterbium- and erbium-doped all-fiber lasers using graphene oxide saturable absorbers
(2014-06-02)
Chen, Hou-Ren
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Tsai, Chih-Ya
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Cheng, Hsin-Ming
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Lin, Kuei-Huei
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Hsieh, Wen-Feng
Broadband graphene oxide/PVA films were used as saturable absorbers (SAs) for mode locking erbium-doped fiber laser (EDFL) and ytterbium-doped fiber laser (YDFL) at 1.06 mu m and 1.55 mu m. They provide modulation depths of 3.15% and 6.2% for EDFL and YDFL, respectively. Stable self-starting mode-locked pulses are obtained for both lasers, confirming that the graphene oxide is cost-effective. We have generated mode-locked pulses with spectral width, repetition rate, and pulse duration of 0.75 nm, 9.5 MHz, and 2.7 ps. This is the shortest pulse duration directly obtained from an all-normal-dispersion YDFL with graphene-oxide saturable absorber. (C) 2014 Optical Society of America
Effective absorption enhancement in dielectric thin-films with embedded paired-strips gold nanoantennas
(2014-06-02)
Yang, Zih-Ying
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Chen, Kuo-Ping
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照明與能源光電研究所
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影像與生醫光電研究所
;
Institute of Lighting and Energy Photonics
This study focuses on determining the optimized thickness of an absorbing thin-film with embedded gold nanoantennas, for absorption enhancement. Gold paired-strips nanoantennas with small gaps have been proposed for light trapping because of the high localized electric field in the gap due to resonance. Paired-strips nanoantennas with small gaps produce higher effective absorption compared to single-strip gratings. From the average absorption two-dimensional map, the absorption enhancement may increase by a factor of up to 20 for gold paired-strips nanoantennas embedded in a 100 nm thick P3HT:PCBM thin-film. (C) 2014 Optical Society of America
Intensify the application of ZnO-based nanodevices in humid environment: O-2/H-2 plasma suppressed the spontaneous reaction of amorphous ZnO nanowires
(2014-06-02)
Lai, Chun-Yen
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Chien, Tzu-Chiao
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Lin, Ting-Yi
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Ke, Teng
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Hsu, Shih-Han
In this work, we have demonstrated that amorphous ZnO nanobranches (a-ZnO NBs) could spontaneously react from the crystalline ZnO NWs (c-ZnO NWs) at specific humid environment. The spontaneous reaction mechanism and result can be analyzed by humidity controlling and optical microscope (OM)/scanning electron microscope (SEM)/Kelvin probe force microscopy (KPFM)/transmission electron microscopy (TEM) system. We can make the c-ZnO NWs spontaneous reaction happen at different humid environments and suppress the a-ZnO NBs spontaneous reaction by oxygen/hydrogen plasma surface passivation. The hydrogen plasma surface treatment also can improve the UV sensing sensitivity more than twofold. This work provides the mechanism and methods of the a-ZnO NBs spontaneous growth and offers the passivation treatment for strengthening and enhancing ZnO-based nanodevice application in humid environment and UV light detection, respectively.
Growth and characterization of Cu(In,Ga)Se-2 thin films by nanosecond and femtosecond pulsed laser deposition
(2014-06-02)
Chen, Shih-Chen
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Hsieh, Dan-Hua
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Jiang, Hsin
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Liao, Yu-Kuang
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Lai, Fang-I
In this work, CuIn1-xGaxSe2 (CIGS) thin films were prepared by nanosecond (ns)- and femtosecond (fs)-pulsed laser deposition (PLD) processes. Different film growth mechanisms were discussed in perspective of the laser-produced plasmas and crystal structures. The fs-PLD has successfully improved the inherent flaws, Cu-2 (-) Se-x, and air voids ubiquitously observed in ns-PLD-derived CIGS thin films. Moreover, the prominent antireflection and excellent crystalline structures were obtained in the fs-PLD-derived CIGS thin films. The absorption spectra suggest the divergence in energy levels of radiative defects brought by the inhomogeneous distribution of elements in the fs-PLD CIGS, which has also been supported by comparing photoluminescence (PL) spectra of ns- and fs-PLD CIGS thin films at 15 K. Finally, the superior carrier transport properties in fs-PLD CIGS were confirmed by fs pump-probe spectroscopy and four-probe measurements. The present results indicate a promising way for preparing high-quality CIGS thin films via fs-PLD.
Demonstration of a broad band spectral head-mounted display with freeform mirrors
(2014-06-02)
Pan, Jui-Wen
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Che-Wen, Chiang
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Huang, Kuan-Da
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Wu, Chung-Yu
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光電系統研究所
It has been demonstrated that electrical stimulation of the retina can produce visual perception for blind patients suffering from macular degeneration and retinitis pigmentosa. In order to let the retinal chip generate enough electrical stimulation, the near infrared ray source is added to enhance the stimulation current. However, it is a challenge to design a head-mounted display (HMD) that covers both visible and infrared rays. Since the HMD system covers such a broad spectral band, large color aberrations will be induced. In order to eliminate these large aberrations, a mirror system is adopted that will create a no color aberration system. We also use two freeform mirrors (FFMs) to reduce residual aberrations such as spherical aberrations and coma. The FFMs serve as the near-eye viewing optics that magnifies the image which is displayed through a microdisplay. Based on a 0.61 in. microdisplay, the HMD system demonstrates a diagonal field of view (FOV) of 30 degree and an f/# of 3.75, with an exit pupil diameter of 8 mm and eye clearance of 15mm. (C) 2014 Optical Society of America
Pervasive brain monitoring and data sharing based on multi-tier distributed computing and linked data technology
(2014-06-03)
Zao, John K.
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Gan, Tchin-Tze
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You, Chun-Kai
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Chung, Cheng-En
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Wang, Yu-Te
EEG-based Brain-computer interfaces (BCI) are facing basic challenges in real-world applications. The technical difficulties in developing truly wearable BCI systems that are capable of making reliable real-time prediction of users\' cognitive states in dynamic real-life situations may seem almost insurmountable at times. Fortunately, recent advances in miniature sensors, wireless communication and distributed computing technologies offered promising ways to bridge these chasms. In this paper, we report an attempt to develop a pervasive on-line EEG-BCI system using state-of-art technologies including multi-tier Fog and Cloud Computing, semantic Linked Data search, and adaptive prediction/classification models. To verify our approach, we implement a pilot system by employing wireless dry-electrode EEG headsets and MEMS motion sensors as the front-end devices, Android mobile phones as the personal user interfaces, compact personal computers as the near-end Fog Servers and the computer clusters hosted by the Taiwan National Center for High-performance Computing (NCHC) as the far-end Cloud Servers. We succeeded in conducting synchronous multi-modal global data streaming in March and then running a multi-player on-line EEG-BCI game in September, 2013. We are currently working with the ARL Translational Neuroscience Branch to use our system in real-life personal stress monitoring and the UCSD Movement Disorder Center to conduct in-home Parkinson\'s disease patient monitoring experiments. We shall proceed to develop the necessary BCI ontology and introduce automatic semantic annotation and progressive model refinement capability to our system.
Pervasive brain monitoring and data sharing based on multi-tier distributed computing and linked data technology
(2014-06-03)
Zao, John K.
;
Gan, Tchin-Tze
;
You, Chun-Kai
;
Chung, Cheng-En
;
Wang, Yu-Te
EEG-based Brain-computer interfaces (BCI) are facing basic challenges in real-world applications. The technical difficulties in developing truly wearable BCI systems that are capable of making reliable real-time prediction of users' cognitive states in dynamic real-life situations may seem almost insurmountable at times. Fortunately, recent advances in miniature sensors, wireless communication and distributed computing technologies offered promising ways to bridge these chasms. In this paper, we report an attempt to develop a pervasive on-line EEG-BCI system using state-of-art technologies including multi-tier Fog and Cloud Computing, semantic Linked Data search, and adaptive prediction/classification models. To verify our approach, we implement a pilot system by employing wireless dry-electrode EEG headsets and MEMS motion sensors as the front-end devices, Android mobile phones as the personal user interfaces, compact personal computers as the near-end Fog Servers and the computer clusters hosted by the Taiwan National Center for High-performance Computing (NCHC) as the far-end Cloud Servers. We succeeded in conducting synchronous multi-modal global data streaming in March and then running a multi-player on-line EEG-BCI game in September, 2013. We are currently working with the ARL Translational Neuroscience Branch to use our system in real-life personal stress monitoring and the UCSD Movement Disorder Center to conduct in-home Parkinson's disease patient monitoring experiments. We shall proceed to develop the necessary BCI ontology and introduce automatic semantic annotation and progressive model refinement capability to our system.
Quantum Localization of Coherent pi-Electron Angular Momentum in (P)-2,2 \'-Biphenol
(2014-06-05)
Yamaki, Masahiro
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Mineo, Hirobumi
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Teranishi, Yoshiaki
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Hayashi, Michitoshi
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Fujimura, Yuichi
Controlling g-electrons with delocalized character is one of the fundamental issues in femtosecond and attosecond chemistry. Localization of pi-electron rotation by using laser pulses is expected to play an essential role in nanoscience. The pi-electron rotation created at a selected aromatic ring of a single molecule induces a local intense electromagnetic field, which is a new type of ultrafast optical control functioning. We propose a quantum localization of coherent pi-electron angular momentum in (P)-2,2\'-biphenol, which is a simple, covalently linked chiral aromatic ring chain molecule. The localization considered here consists of sequential two steps: the first step is to localize the pi-electron angular momentum at a selected ring of the two benzene rings, and the other is to maintain the localization. Optimal control theory was used for obtaining the optimized electric fields of linearly polarized laser pulses to realize the localization. The optimal electric fields and the resultant coherent electronic dynamics are analyzed.
Quantum Localization of Coherent pi-Electron Angular Momentum in (P)-2,2 '-Biphenol
(2014-06-05)
Yamaki, Masahiro
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Mineo, Hirobumi
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Teranishi, Yoshiaki
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Hayashi, Michitoshi
;
Fujimura, Yuichi
Controlling g-electrons with delocalized character is one of the fundamental issues in femtosecond and attosecond chemistry. Localization of pi-electron rotation by using laser pulses is expected to play an essential role in nanoscience. The pi-electron rotation created at a selected aromatic ring of a single molecule induces a local intense electromagnetic field, which is a new type of ultrafast optical control functioning. We propose a quantum localization of coherent pi-electron angular momentum in (P)-2,2'-biphenol, which is a simple, covalently linked chiral aromatic ring chain molecule. The localization considered here consists of sequential two steps: the first step is to localize the pi-electron angular momentum at a selected ring of the two benzene rings, and the other is to maintain the localization. Optimal control theory was used for obtaining the optimized electric fields of linearly polarized laser pulses to realize the localization. The optimal electric fields and the resultant coherent electronic dynamics are analyzed.
交大e-News第164期
(2014-06-05)
Secretariat
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國立交通大學秘書室
Silicone Resin Synthesized by Tetraethoxysilane and Chlorotrimethylsilane Through Hydrolysis- Condensation Reaction
(2014-06-05)
Kuo, Chung-Feng Jeffrey
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Chen, Jiong-Bo
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Shih, Chung-Yang
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Huang, Chao-Yang
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機械工程學系
Silicone pressure-sensitive adhesives compositions contain a polydimethylsiloxane and a silicone resin, which can enhance the instant bonding ability and bonding strength of the adhesive. In this study, silicone resin was designed to have a low molecular weight and a highly nonpolar chemical structure. The silicone resin was applied to silicone pressure-sensitive adhesives. The molecular structure of silicone resin was characterized by FT-IR, GPC, H-1-NMR, and Si-29-NMR spectroscopic techniques. Properties such as thermal stability, solubility, hydrophobic, and transparent properties were researched and compared. When the chlorotrimethylsilane increased, it appeared that the amount of silanol groups, molecular weight and thermal stability decreased, while the hydrophobic and transparent properties increased. The silicone resin was completely soluble in toluene and xylene. It was also applied to silicone pressure-sensitive adhesives, resulting in good peel adhesion. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40317.
Stacked Gate Structure, Metal-Oxide-Semiconductor Including the Same, and Method for Manufacturing the Stacked Gate Structure
(2014-06-05)
LIN Yueh-Chin
;
CHANG Edward Yi
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CHUANG Ting-Wei
The invention provides a stacked gate structure and metal-oxide-semiconductor including the same, and method for manufacturing the stacked gate structure. The stacked gate structure comprises a substrate, a semiconductor layer positioned on the substrate, a gate dielectric positioned on the semiconductor layer, and a gate electrode layer positioned on the gate dielectric, which the gate dielectric comprises a composite oxide layer composed of lanthanum oxide (La2O3) and hafnium oxide (HfO2).
AUTONOMOUS ELECTRONIC APPARATUS AND NAVIGATION METHOD THEREOF
(2014-06-05)
Song Kai-Tai
;
Hung Shang-Chun
An autonomous electronic apparatus and a navigation method thereof are provided. The navigation method includes the following steps. Firstly, a calling signal from a target is received through a wireless sensor network. A position relationship between the target and the autonomous electronic apparatus is analyzed to generate a first speed. Next, an image set is captured and an image relationship between the image set and the target is analyzed to generate a second speed. Afterwards, a weighting value related to the position relationship is calculated. Besides, a moving speed is calculated according to the weighting value, the first speed and the second speed, and a moving status of the autonomous electronic apparatus moving toward the target is controlled via the moving speed.
High density GaN/AlN quantum dots for deep UV LED with high quantum efficiency and temperature stability
(2014-06-05)
Yang, Weihuang
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Li, Jinchai
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Zhang, Yong
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Huang, Po-Kai
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Lu, Tien-Chang
High internal efficiency and high temperature stability ultraviolet (UV) light-emitting diodes (LEDs) at 308 nm were achieved using high density (2.5 x 10(9) cm(-2)) GaN/AlN quantum dots (QDs) grown by MOVPE. Photoluminescence shows the characteristic behaviors of QDs: nearly constant linewidth and emission energy, and linear dependence of the intensity with varying excitation power. More significantly, the radiative recombination was found to dominant from 15 to 300 K, with a high internal quantum efficiency of 62% even at room temperature.
PULSE-BASED FLIP FLOP
(2014-06-05)
LEE Chen-Yi
;
SUNG Wei-Hao
;
LEE Ming-Che
A pulse-based flip-flop that latches a data input signal to convert the data input signal into a data output signal in response to a first clock signal and the second clock signal. The pulse-based flip-flop includes a pulse generator and a data latch. The pulse generator includes a first inverter and a signal delay circuit to receive the first clock signal and generate the second clock signal; the data latch includes a delivery circuit, a latch circuit and a control circuit. The data latch is used to latch the data input signal and output the data output signal in response to the first and the second clock signals.
SOLAR CELL MODULE AND METHOD OF FABRICATING THE SAME
(2014-06-05)
Chen Fang-Chung
;
Chou Chun-Hsien
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Chuang Jui-Kang
;
Lin Yen-Tseng
A solar cell module and a method of fabricating the same are provided. The method includes providing a solution having a luminescent dye, mixing the solution with a first waveguide material to obtain a first mixture, and placing the first mixture and a second mixture having nano-powder and a second waveguide material into a mold to form a waveguide body having a first layer body and a second layer body stacked on the first layer body. The waveguide body has a top surface, a bottom surface opposing to the top surface, and a lateral surface connecting the top surface with the bottom surface. At least one solar cell is disposed in the mold and embedded in the waveguide body, to enlarge a light reception area and light collection.
DYNAMIC RECONFIGURABLE HETEROGENEOUS PROCESSOR ARCHITECTURE WITH LOAD BALANCING AND DYNAMIC ALLOCATION METHOD THEREOF
(2014-06-05)
CHUNG Chung-Ping
;
YANG Hui-Chin
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CHEN Yi-Chi
A dynamic reconfigurable heterogeneous processor architecture with load balancing and dynamic allocation method thereof is disclosed. The present invention uses a work control logic unit to detect load imbalance between different types of processors, and employs a number of dynamic reconfigurable heterogeneous processors to offload the heavier loaded processors. Hardware utilization of such design can be enhanced, and variation in computation needs among different computation phases can be better handled. To design the dynamic reconfigurable heterogeneous processors, a method of how to choose the basic building blocks and place the routing components is included. With the present invention, performance can be maximized at a minimal hardware cost. Hence the dynamic reconfigurable heterogeneous processor(s) so constructed and the load balancing and dynamic allocation method together will have the best performance at least cost.