Browsing by Issue Date, starting with "2009-03-16"

Now showing 1 - 20 of 51194

Compact efficient Q-switched eye-safe laser at 1525 nm with a double-end diffusion-bonded Nd:YVO(4) crystal as a self-Raman medium
(2009-03-16)
Chang, Y. T.
;
Su, K. W.
;
Chang, H. L.
;
Chen, Y. F.
;
電子物理學系
We report on an efficient Q-switched eye-safe laser at 1525 nm with a double-end diffusion-bonded Nd:YVO(4) crystal as a self-Raman gain medium. A diffusion-bonded crystal not only reduces the thermal effects but also increase the interaction length for the stimulated Raman scattering. With an input pump power of 17.2 W, average power of 2.23 W at the first-Stokes wavelength of 1525 nm is generated at a pulse repetition rate of 40 kHz, corresponding to a conversion efficiency of 13%. (C) 2009 Optical Society of America
邊射型高功率雷射二極體結構
(2009-03-16)
盧廷昌
;
陳瓊華
一種邊射型高功率雷射二極體結構,其係具有啁啾(chirp)型周期性分佈之複數模態延展子層,其近場光型會呈現L形,且光場強度高的部分與多重量子井重疊良好,因此可獲得良好的光侷限因子,而且,光場強度低的部分會盡量往n型披覆層延伸,如此可降低邊射型高功率雷射二極體鏡面的光功率密度,並降低垂直發散角,增加此邊射型高功率雷射二極體的壽命。
具有奈米線通道之非揮發性記憶體元件及其製造方法
(2009-03-16)
林鴻志
;
蘇俊榮
;
徐行徽
一種具有奈米線通道之非揮發性記憶體元件及其製造方法,乃利用側向蝕刻方式,使側閘極側壁內縮來形成奈米線模型,從而將奈米線通道製作於側閘極側壁的介電層上,完成具有奈米線通道及透過雙閘極控制之非揮發性記憶體元件,此非揮發性記憶體元件係可達到提升資料寫入和抹除效率,並具有低電壓操作的能力,而且,本發明可在成本低和簡易步驟之製程下,完成重複性高及可量產化之奈米線元件製作。
Side-mode transmission diagnosis of a multichannel selectable injection-locked Fabry-Perot Laser Diode with anti-reflection coated front facet
(2009-03-16)
Liao, Yu-Sheng
;
Kuo, Hao-Chung
;
Chen, Yung-Jui
;
Lin, Gong-Ru
;
光電工程學系
Theory and experiments on the side-mode-suppression-ratio (SMSR) enhancement and the linewidth reduction of a Fabry-Perot laser diode (FPLD) side-mode-injection-locked by using another FPLD are demonstrated to realize its potential application as a DWDM transmitter source. The SMSR, the spectral linewidth and the linewidth enhancement factor are simulated to realize the limitation of the FPLD-FPLD link under side-mode injection-locking condition. A degradation of the linewidth enhancement factor from 1.5 to 2.1 is observed due to the slave FPLD injection-locked at principle- and side-mode conditions. Up to 22-channel selectability of the 2.5 Gbit/s directly modulated FPLD based transmitter under side-mode injection-locking is demonstrated with a SMSR >35 dB, a Q-factor 6.8-9.2, a locking range of 24 nm, a power penalty of -0.7 dB, and a BER of 10(-10) at -17 dBm. The side-mode injection-locked FPLD shows high-quality transmission performance and meet the demand for cost-effective and high-capability 2.5 Gbit/s WDM systems. (C) 2008 Optical Society of America
OFDM／OFDMA無線通訊系統之前置序列檢測及整數載波偏移估計方法
(2009-03-16)
洪崑健
;
林大衛
在OFDM/OFDMA無線多細胞通訊系統中,任何欲進入系統之用戶台都需要先和基地台取得時間與頻率同步並取得基地台識別碼,其中頻率同步一般需估計分數載波偏移和整數載波偏移(分數與整數係將載波偏移表示為相鄰子載波間距之倍數後的分數與整數部份)。本發明設用戶台首先完成時間與分數頻率同步,其次進行整數載波偏移之估計及基地台識別碼之檢測,本發明同時考慮並解決整數載波偏移之估計及基地台識別碼之檢測。本發明解決多通道干擾下的訊號檢測問題,求得理論最佳解,並推出簡化的近似最佳解,其特徵在於採用頻域濾波來計算相關係數(correlation),如決策量値(metric),可大幅降低運算複雜度,而僅對精準度有些微影響。此外,本發明又提出數種簡化的運算方法,可以免用乘法器。上述頻域濾波概念極具延伸性,故可廣泛使用在相關的訊號序列偵測上。
光鉗裝置及系統
(2009-03-16)
趙昌博
;
施凱騰
;
丘祺緯
本發明提供一種光鉗,其包含一光源、一準直器以及一變焦透鏡。該光源能產生一光束,並且透過一光纖傳遞該光束。該準直器固定於該光纖之一端,用以修正該光束成為一平行光束。此外,該變焦透鏡則固定於該準直器之一表面上,用以接收該平行光束,並且將該平行光束聚焦於至少一微小樣本上。
Phase-change memory devices based on gallium-doped indium oxide
(2009-03-16)
Wang, S. -L.
;
Chen, C. -Y.
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Hsieh, M. -K.
;
Lee, W. -C.
;
Kung, A. H.
We report repetitive phase-change memory (PCM) activity via the high- to low-resistance state transition in gallium-doped indium oxide (Ga:InO) induced by nanosecond electric pulses. The amorphous-to-crystalline phase transition of Ga:InO is found to occur at a crystallization temperature of similar to 250 degrees C with an activation energy of 1.27 +/- 0.07 eV. At the phase transition, we observe a change in two orders of magnitude in the PCM-device resistance, which can be correlated with the formation of (211) and {222} crystallites of bixbyite cubic In(2)O(3). We ascribe the phase-change mechanism to the Joule heating effect in Ga:InO.
Compact efficient Q-switched eye-safe laser at 1525 nm with a double-end diffusion-bonded Nd:YVO4 crystal as a self-Raman medium
(2009-03-16)
Chang, Y. T.
;
Su, K. W.
;
Chang, H. L.
;
Chen, Y. F.
;
電子物理學系
We report on an efficient Q-switched eye-safe laser at 1525 nm with a double-end diffusion-bonded Nd:YVO4 crystal as a self-Raman gain medium. A diffusion-bonded crystal not only reduces the thermal effects but also increase the interaction length for the stimulated Raman scattering. With an input pump power of 17.2 W, average power of 2.23 W at the first-Stokes wavelength of 1525 nm is generated at a pulse repetition rate of 40 kHz, corresponding to a conversion efficiency of 13%. (C) 2009 Optical Society of America
功率因數修正方法及其裝置
(2009-03-16)
陳鴻祺
一種應用於昇壓型轉換器之功率因數修正方法及其裝置。功率因數修正方法係先由回授輸入與輸出電壓,產生開關切換參考信號;再由轉換器回授之輸出電壓與電壓命令之電壓誤差,經電壓控制器取得相位位移量,進而利用相位位移器,平移此開關切換參考信號,決定出開關切換控制信號,再經由比較器比較開關切換控制信號與三角波信號,產生最終開關切換信號,進而調整輸入電流波形跟隨電壓波形,以修正功率因數。應用此方法之功率因數控制器僅用單一電壓迴路,無須回授電流,即可修飾電流波形,大大簡化電路的複雜度。
Theoretical investigation of polarization-insensitive data format conversion of RZ-OOK to RZ-BPSK in a nonlinear birefringent fiber
(2009-03-16)
Wei, C. C.
;
Astar, W.
;
Chen, J.
;
Chen, Y. -J.
;
Carter, G. M.
Polarization-insensitive conversion of return-to-zero (RZ) ON-OFF keying (RZ-OOK) to RZ binary phase-shift keying (RZ-BPSK) has been achieved by cross-phase modulation (XPM) in a nonlinear birefringent fiber. This work presents a theoretical analysis of the dependence of format conversion on pump-probe detuning, and the pump state-of-polarization (SOP) that can fluctuate unpredictably in a realistic system. An investigation of the impact of pump polarization fluctuation on receiver sensitivity and receiver optimal threshold for the converted RZ-BPSK probe is also carried out. It was found that although the desired XPM-induced pi phase shift can be achieved by launching both the RZ-OOK pump and the probe along the same birefringent axis of the fiber, the phase shift degrades to pi/3 the SOP of the RZ-OOK pump unpredictably switches to the other axis of the fiber, resulting in a large receiver sensitivity penalty fluctuation of 14 dB. By contrast, launching the probe at 45 degrees relative to the birefringent axes can reduce the polarization-dependent receiver sensitivity penalty fluctuation to about 2 dB as the SOP of the RZ-OOK pump is swept over the Poincare sphere. These conclusions are in good agreement with recently published experimental results. (C) 2009 Optical Society of America
同軸體積全像儲存系統
(2009-03-16)
孫慶成
;
余業緯
;
謝舒菁
一種同軸體積全像儲存系統,其係針對訊號調制部分加以改良,亦即在參考光的部分加上一透鏡元件或利用一空間相位調制器進行相位調制,因此,本發明之改良架構不但對於角度及位置較不靈敏而擁有生產時誤差容忍度較佳的優點,而且不需大幅提高光源的雷射功率,所以增加了技術實現的可行性,可以廣泛應用於光學儲存產業之各類光學儲存產品,例如各種光碟機與數位影音光碟機。
應用於生物晶片之電源控制裝置及其操作方法
(2009-03-16)
吳重雨
;
林伯剛
;
林俐如
;
楊文嘉
;
萬諶
本發明揭露一種應用於一生物晶片之電源控制裝置。該生物晶片包含M個區域且每一區域各自包含複數個生物細胞。該電源控制裝置包含一時脈產生模組、一組合式電路及M個控制模組。該時脈產生模組用以產生一時脈訊號。該組合式電路用以根據該時脈訊號產生M個具有不同相位之控制訊號。該M個控制模組中之一第096134044P01.bmp控制模組係根據第096134044P02.bmp控制訊號控制第096134044P03.bmp區域之一電源開啓或關閉。當該第096134044P04.bmp區域之該電源被開啓,該第096134044P05.bmp區域中之該等生物細胞被觸發。該等生物細胞具有一觸發-還原時間;該第096134044P06.bmp區域之該電源所對應之一開啓時間間隔小於該觸發-還原時間。
Fabrication of Patterned Superhydrophobic Polybenzoxazine Hybrid Surfaces
(2009-03-17)
Liao, Chun-Syong
;
Wang, Chih-Feng
;
Lin, Han-Ching
;
Chou, Hsin-Yi
;
Chang, Feng-Chih
The hydrophilicity of bis(3-allyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane(B-ala) polybenzoxazine film and superhydrophobic polybenzoxazine-hybrid surface can be controlled through UV exposure to change the ratio of intra to intermolecular hydrogen bonds. A fraction of the intramolecular hydrogen bonding of the as-cured sample will convert into intermolecular hydrogen bonding upon UV exposure and thus results in an increase of hydrophilicity. This simple method allows for manipulating the hydrophilicity at selected regions on a superhydrophobic polybenzoxazine hybrid surface to create a patterned surface with superhydrophobic and superhydrophilic regions. Additionally, we have found that the superhydrophobic polybenzoxazine-silica hybrid surface exhibits good adhesion of water droplets after UV exposure, which can be served as a "mechanical hand" to transfer water droplets from a superhydrophobic surface to a hydrophilic one.
Relationships of Retinal Arteriolar and Venular Diameters with Carotid Intima-Media Thickness: The Beaver Dam Offspring Study
(2009-03-17)
Godreau, Ayleen
;
Klein, Ronald
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Lee, Kristine
;
Klein, Barbara E. K.
;
Schubert, Carla
Pulse-Wave Velocity and Cardiovascular Risk Factors in the Beaver Dam Offspring Study (BOSS) Population
(2009-03-17)
Zhong, Wenjun
;
Cruickshanks, Karen J.
;
Schubert, Carla
;
Javier Nieto, F.
;
Pankow, James S.
Magnetowave Induced Plasma Wakefield Acceleration for Ultrahigh Energy Cosmic Rays
(2009-03-20)
Chang, Feng-Yin
;
Chen, Pisin
;
Lin, Guey-Lin
;
Noble, Robert
;
Sydora, Richard
Magnetowave induced plasma wakefield acceleration (MPWA) in a relativistic astrophysical outflow has been proposed as a viable mechanism for the acceleration of cosmic particles to ultrahigh energies. Here we present simulation results that clearly demonstrate the viability of this mechanism for the first time. We invoke the high frequency and high speed whistler mode for the driving pulse. The plasma wakefield obtained in the simulations compares favorably with our newly developed relativistic theory of the MPWA. We show that, under appropriate conditions, the plasma wakefield maintains very high coherence and can sustain high-gradient acceleration over hundreds of plasma skin depths. Invoking active galactic nuclei as the site, we show that MPWA production of ultrahigh energy cosmic rays beyond ZeV (10(21) eV) is possible.
交大e-News第044期
(2009-03-20)
Secretariat
;
國立交通大學秘書室
在無線通訊系統下適應性RTO的預測方法
(2009-03-21)
黃經堯
;
羅文嶽
;
程士恆
;
陳欽健
因為舊有的TCP傳輸控制方法直接應用在無線通訊上會產生錯誤,例如一些錯誤的控制數據估測導致誤判為網路壅塞,本發明提出一個為適應性RTO(Retransmission Time Out)控制方法來修正。這個控制方法可以動態改變來回傳輸時間的預測値來適應現在的頻寬狀況。因為正確的RTO數値可以藉由新的適應性的來回傳輸時間的預測値來計算出來,所以可以解決由於因頻寬變動造成不正確的RTO數値所造成誤判網路狀況和不必的重新傳輸問題,從而增加TCP在無線系統下的效能。
閘極控制場發射三極元件及該元件之製作方法
(2009-03-21)
曾俊元
;
李佳穎
;
李思毅
;
林鵬
本發明關於低溫下製備具有高長寬比之氧化鋅奈米棒之方法,其可與半導體製程進行整合,可獲得一具有閘極控制之三極場發射元件。該方法主要包括:提供一具有經過定義元件區域之半導體基板;於該經過定義元件區域上分別沉積一介電層及一導電層;於該介電層及導電層上定義出發射體陣列所在位置;以水熱法成長氧化鋅奈米棒於該發射體陣列;及以濕蝕刻法除去非發射體陣列所在位置之部分而獲得閘極控制場發射三極元件。
聆聽自我的《心靈之歌》
(2009-03-22)
黃湘茹
;
Department of Communication and Technology
;
傳播與科技學系
...