Browsing by Author "Pan, C. H."

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2-3 mu m mid infrared light sources using InGaAs/GaAsSb "W" type quantum wells on InP substrates
(2010-11-15)
Pan, C. H.
;
Lin, S. D.
;
Lee, C. P.
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We have investigated the InGaAs/GaAsSb/InAlGaAs/InAlAs type-II "W" quantum wells (QWs) grown on InP substrates by molecular beam epitaxy. The photoluminescence (PL) emission wavelength longer than 2.56 mu m at room temperature (RT) is demonstrated for the first time in this material system. The PL emission peaks of our designed samples can cover a wide range from 2 to 2.5 mu m at cryogenic temperature. The samples show good optical quality that the reduction in integrated PL intensity is only around one order of magnitude from 35 K to RT. We found that the integrated PL intensity decreased as the emission wavelength increased, which is due to the reduction in the electron-hole wave function overlap. This is consistent with the calculated result. In the power dependent PL measurements, the emission peak of "W" type QWs show blue shifts with the excitation power (P-ex) but does not follow the P-ex(1/3) rule as predicted by type-II band bending model. The localized states filling effect gives reasonable explanations for the observed phenomena. (C) 2010 American Institute of Physics. [doi:10.1063/1.3506427]
2-3 mu m mid infrared light sources using InGaAs/GaAsSb "W" type quantum wells on InP substrates
(2010-11-15)
Pan, C. H.
;
Lin, S. D.
;
Lee, C. P.
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We have investigated the InGaAs/GaAsSb/InAlGaAs/InAlAs type-II "W" quantum wells (QWs) grown on InP substrates by molecular beam epitaxy. The photoluminescence (PL) emission wavelength longer than 2.56 mu m at room temperature (RT) is demonstrated for the first time in this material system. The PL emission peaks of our designed samples can cover a wide range from 2 to 2.5 mu m at cryogenic temperature. The samples show good optical quality that the reduction in integrated PL intensity is only around one order of magnitude from 35 K to RT. We found that the integrated PL intensity decreased as the emission wavelength increased, which is due to the reduction in the electron-hole wave function overlap. This is consistent with the calculated result. In the power dependent PL measurements, the emission peak of "W" type QWs show blue shifts with the excitation power (P(ex)) but does not follow the P(ex)(1/3) rule as predicted by type-II band bending model. The localized states filling effect gives reasonable explanations for the observed phenomena. (C) 2010 American Institute of Physics. [doi:10.1063/1.3506427]
Design and modeling of InP-based InGaAs/GaAsSb type-II "W" type quantum wells for mid-Infrared laser applications
(2013-01-28)
Pan, C. H.
;
Lee, C. P.
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We have theoretically studied the InP based InGaAs/GaAsSb /InAlAs type-II "W" quantum wells (QWs) using the eight band k.p theory. The trade-off between the emission wavelength and the magnitude of the transition matrix element was investigated with various structural parameters of the "W" QWs. For the same emission wavelength, the devices with thinner InGaAs/GaAsSb layers and a higher Sb content in GaAsSb could provide higher transition strength. The gain spectra and their peak values at various carrier densities were calculated. We have also found that a more balanced electron and hole masses in the type-II "W" QWs can benefit the material gain. In our designed cases, we have seen that the reduced hole effective mass due to a higher Sb content can partially compensate the gain loss caused by the reduced transition matrix element. Based on the optimized design, a material gain above 10(3) cm(-1) is readily achievable for a single properly designed "W" quantum well. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789634]
Development of dynamically artificial flowers driven by Shape Memory Alloy and Pulse Width Modulation
(2015)
Pan, C. H.
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Wang, Y. B.
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Pan, H. Y.
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機械工程學系
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Department of Mechanical Engineering
Artificial flowers are mainly static objects. If we can make them movable with actuating mechanisms, sensors and controllers, this will make them more lively and entertaining. The aim of this paper is to develop artificial flower ornaments with dynamic, modular, programmable and green-energy characteristics. The dynamically artificial flower ornaments show the performances: bending of stems, blooming of petals, spreading of fragrance and flapping of butterflies. Besides, solar power to simulate photosynthesis (it is just an analogy to actual photosynthesis) will be used to energize the dynamically artificial flower ornaments. Instead of using conventional mechanisms and electromagnetic motor to actuate the flower ornaments, we use shape memory alloy (SMA) as actuators and pulse width modulation (PWM) as drive circuit to avoid complication, lager volume and noise generation of the components. Four types of the SMA actuators are made of SMA wire (Ti50%-Ni45%-Cu5%) with one way shape memory effect and 0.6mm in diameter. The performance of each SMA actuator is evaluated. By using PWM, the SMA actuators have high response time and low energy consumption in acting cycle.
Low repetition rate and broad frequency tuning from a grating-coupled passively mode-locked quantum dot laser
(2013-11-18)
Cheng, H. C.
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Wu, Q. Y.
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Pan, C. H.
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Lee, C. P.
;
Lin, G.
Passively mode-locked quantum dot lasers with a grating-coupled external cavity arrangement are investigated. A broad repetition-rate tuning range of fundamental mode-locking from 2GHz to a record-low frequency of 79.3 MHz is achieved with selecting the wavelength at 1.28 mu m. A narrow RF linewidth of similar to 25 Hz and an intrinsic linewidth as low as 0.15 Hz are also obtained. (C) 2013 AIP Publishing LLC.
Regulation of angiotensin converting enzyme II by angiotensin peptides in human cardiofibroblasts
(2010-09-01)
Lin, C. S.
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Yang, T. H.
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Wen, C. H.
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Pan, C. H.
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