Browsing by Author "Hwang, Yi-Chia"

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A ZnO/InN/GaN Heterojunction Photodetector with Extended Infrared Response
(2015)
Hsu, Lung-Hsing
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Hsu, Shun-Chieh
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Lee, Hsin-Ying
;
Tsai, Yu-Lin
;
Lin, Da-Wei
An extended infrared photoresponse is observed in a ZnO/InN/GaN heterojunction diode with InN grown by MOCVD. The external quantum efficiency is measured between 1200 and 1800 nm and can be as high as 3.55%.
Enhanced photocurrent of a nitride-based photodetector with InN dot-like structures
(2014-12-01)
Hsu, Lung-Hsing
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Lin, Chien-Chung
;
Han, Hau-Vei
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Lin, Da-Wei
;
Lo, Yen-Hua
The InN dot-like layer was applied in the gallium nitride based material for the purpose of infrared photodetectors (PDs). This InN layer was grown by a low-pressure metal organic chemical vapor deposition technology under different growth temperatures. The X-ray diffraction patterns provide the information of crystal structure and the hexagonal orientation was detected. The Raman shifts and photoluminescence were also used to characterize the quality of InN film. Finally, the fabricated Schottky-type photodetector was tested under a solar simulator and a long-wavelength laser (lambda = 1550nm). The measurements show a highly linear relation between photo-generated currents and laser powers for the wavelength of 1550 nm. In the photonic detection range suitable for optical fiber communiation, a quantum efficiency of 9.2% can be observed. (C) 2014 Optical Society of America
InN-based heterojunction photodetector with extended infrared response
(2015-11-30)
Hsu, Lung-Hsing
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Kuo, Chien-Ting
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Huang, Jhih-Kai
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Hsu, Shun-Chieh
;
Lee, Hsin-Ying
The combination of ZnO, InN, and GaN epitaxial layers is explored to provide long wavelength photodetection capability in the GaN based materials. Growth temperature optimization was performed to obtain the best quality of InN epitaxial layer in the MOCVD system. The temperature dependent photoluminescence (PL) can provide the information about thermal quenching in the InN PL transitions and at least two non-radiative processes can be observed. X-ray diffraction and energy dispersive spectroscopy are applied to confirm the inclusion of indium and the formation of InN layer. The band alignment of such system shows a typical double heterojunction, which is preferred in optoelectronic device operation. The photodetector manufactured by this ZnO/GaN/InN layer can exhibit extended long-wavelength quantum efficiency, as high as 3.55%, and very strong photocurrent response under solar simulator illumination. (C) 2015 Optical Society of America
Microwave behavior of a monolithic dual-wavelength DFB laser based on current model
(2020-09-15)
Huang, Chung-Ping
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Huang, Yu-Ming
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Hwang, Yi-Chia
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Dong, Yao-Zhong
;
Hsu, Shun-Chieh
A driving current based model describing the optical heterodyne output of a monolithic dual-wavelength DFB laser is established. The linear relationship between the driving current and the laser output wavelength was applied to obtain the simple equation for this purpose. Actual measured data from the real devices were used for the initial parameter extraction and the practical model can then be built. By using this model, the influence of different laser parameters towards the radio frequency signal generation and different current configuration on the output characteristic can be demonstrated. This can facilitate the future design of such integrated photonic devices.
Modeling of Current Dependent Microwave Behavior of a Two-Section DFB Laser
(2015)
Hwang, Yi-Chia
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Dong, Yao-Zhong
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Hsu, Shun-Chieh
;
Lin, Chien-Chung
;
光電系統研究所
A current dependent model of RF generation is developed for the dual wavelength lasers. Because of the nature of current based operation, it is more convenient to have current as the main variable. From the numerical analysis, certain parameters such as wavelength change rate and linewidth enhancement factor (LEF) can affect the generated RF power more substantially than other parameters.
Optical Properties of InN-Based Photo detection Devices
(2015)
Hsu, Lung-Hsing
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Lin, Chien-Chung
;
Hwang, Yi-Chia
;
Su, Chen-Fung
;
Lin, Shih-Yen
The InN capped with GaN structures is promising for extended visible and infrared absorption. The low growth temperature of GaN/InN epitaxy was fabricated by a low-pressure metal organic chemical vapor deposition system. The strain effect and mixed InxGa1-xN complex of the GaN/InN layer were investigated via Raman and photoluminescence (PL) measurements. The capping GaN with similar growth temperature of previous InN growth induces the gallium diffusion mechanism to form InxGa1-xN complex. The blue-shift phenomenon of multiple GaN/InN peaks with increasing growth temperature was attributed to residual strain and higher Ga content of InGaN. A ZnO/GaN/InN photodetection device is demonstrated with extended IR response, and the quantum efficiency is 2.28%.
Tunable microwave generation of a monolithic dual-wavelength distributed feedback laser
(2014-06-02)
Lo, Yen-Hua
;
Wu, Yu-Chang
;
Hsu, Shun-Chieh
;
Hwang, Yi-Chia
;
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