Browsing by Author "Liu, Y. C."

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A high-speed 850-nm optical receiver by integrating Si photodiode and CMOS IC
(2008-01-01)
Hsin, Y. M.
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Huang, W. K.
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Liu, Y. C.
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Yan, B. E.
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Chen, W. Z.
In this work, three approaches are proposed to implement high-speed 850-nm optical receivers fully in standard bulk 0.18 pm silicon (Si) CMOS technology. In the first approach, the lateral p-i-n photodiode (PD) with designed block well to limit the photocarriers being generated from the laterally depleted regions is integrated in optical receiver. The receiver consists of TIA, LA, offset-cancellation-network and buffer to provide a conversion gain of 110 dB Omega and data rate of 2.5 Gbps operation. In the second receiver, the spatially modulated PD (SMPD) with -3 dB bandwidth of 590 MHz is integrated in optical receiver with the extra adaptive equalizer and demonstrates a data rate of 3.125 Gbps. Finally, the proposed novel structure of PD eliminates the slow diffusion photocarriers by using body contact design to create a new current path under the PD. A bandwidth of 2.8 GHz with 100 % improvement in PD is obtained. The eye diagrams of PD with cable connected amplifiers at 2.5 Gbps, 4 Gbps and 5 Gbps are demonstrated. Furthermore, the optical receiver's optical-electrical (O-E) conversion bandwidth is also increased from 3.6 GHz to 4.3 GHz. To our knowledge, these are the highest O-E conversion bandwidth of the PD and optical receiver ever reported by using the standard bulk 0.18 mu m Si CMOS technology.
Compact efficient high-power triple-color Nd:YVO4 yellow-lime-green self-Raman lasers
(2020-03-01)
Liu, Y. C.
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Chen, C. M.
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Hsiao, J. Q.
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Pan, Y. Y.
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Tsou, C. H.
A novel, to the best of our knowledge, approach is developed to realize a high-power compact efficient yellow-lime-green triple-color Nd : YVO4 self-Raman laser. The 588 nm yellow laser, the 559 nm lime laser, and the 532 nm green laser are converted from the 1064 nm fundamental wave and the 1176 nm Stokes Raman field. The simultaneous three-color operation is accomplished with three stages to step-by-step generate the 588 nm, 559 nm, and 532 nm lasers by using three different lithium triborate (LBO) crystals. By tuning the temperature of each individual LBO crystal, the 588 nm, 559 nm, and 532 nm output powers can be nearly the same and concurrently up to 2.4W at the incident pump power of 30 W, corresponding to a conversion efficiency of 24% for the total output power. (C) 2020 Optical Society of America
Compact optical curvature sensor with a flexible microdisk laser on a polymer substrate
(2009-09-15)
Shih, M. H.
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Hsu, K. S.
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Kunag, Wan
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Yang, Y. C.
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Wang, Y. C.
We demonstrate a chip-scale compact optical curvature sensor. It consists of a low threshold InGaAsP microdisk laser on a flexible polydimethylsiloxane polymer substrate. The curvature dependence of lasing wavelength was characterized by bending the cavity at different bending radii. The measurements showed that the lasing wavelength decreases monotonously with an increasing bending curvature. A good agreement between experiment and three-dimensional finite-difference time-domain simulation was also obtained. The sensitivity of the compact device to the bending curvature is -23.7 nm/mm from the experiment. (C) 2009 Optical Society of America
Criterion for optimizing high-power acousto-optically Q-switched self-Raman yellow lasers with repetition rates up to 500 kHz
(2020-04-01)
Chen, Y. F.
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Chen, K. Y.
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Liu, Y. C.
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Chen, C. M.
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Tsou, C. H.
The criterion for optimizing the high-power acousto-optically Q-switched self-Raman yellow laser is originally explored for the repetition rate within 100-500 kHz. The minimum allowed value for the gate-open time is experimentally verified to be determined by the pulse buildup time. By using the minimum allowed gate-open time, the highest conversion efficiency can be achieved to raise the output power by approximately 20% in comparison with the conventional results. At a repetition rate of 200 kHz, the maximum output power at 588 nm can be up to 8.8 W at an incident pump power of 26 W. Furthermore, a practical formula is developed to accurately calculate the threshold pump power as a function of the gate-open time for a given repetition rate. (C) 2020 Optical Society of America
Efficient high-power continuous-wave lasers at green-lime-yellow wavelengths by using a Nd:YVO4 self-Raman crystal
(2019-02-04)
Chen, Y. F.
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Pan, Y. Y.
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Liu, Y. C.
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Cheng, H. P.
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Tsou, C. H.
Efficient high-power continuous-wave Nd:YVO4 visible lasers at versatile wavelengths of 532 (green). 559 (lime). and 588 nm (yellow) are demonstrated to be achieved by using the identical cavity mirrors and gain medium. A dichroic coating is deposited on one end surface of the gain medium to gather the backward green-yellow emission. The green. lime. and yellow outputs are individually optimized by using different phase-matched lithium triborate (LBO) crystals for second harmonic generation (SHG) of the fundamental field, sum frequency generation (SFG) of the fundamental and the stimulated Raman fields. and SHG of the stimulated Raman field, respectively. At a pump power of 31.6 W, the output powers at 532, 559, and 588 nm can be up to 6.8. 5.4. and 3.1 W. The high efficient and compact Nd:YVO4 lasers at green-lime-yellow wavelengths can be potentially beneficial to future applications in retinal photocoagulation. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Efficient high-power dual-wavelength lime-green Nd:YVO4 lasers
(2019-03-15)
Chen, Y. F.
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Liu, Y. C.
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Pan, Y. Y.
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Gu, D. Y.
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Cheng, H. P.
An efficient high-power dual-wavelength lime-green Nd:YVO4 self-Raman laser is inventively developed by using two different lithium triborate (LBO) crystals. The first and second LBO crystals are employed to generate the 559 nm lime and 532 nm green lasers, respectively. The temperature of the first LBO crystal is fixed at the optimal phase matching, whereas the temperature of the second LBO crystal is tuned to flexibly control the relative strengths between the 532 and 559 nm waves. When the temperature of the second LBO crystal is set for the maximal total output power, the 532 and 559 nm output powers, respectively, are 7.1 and 2.9 W at a pump power of 31.6 W, corresponding to a conversion efficiency of 31.6%. When the temperature is controlled for the balanced output, the 532 and 559 nm powers, respectively, are 4.3 and 4.2 W at a pump power of 31.6 W, corresponding to a conversion efficiency of 26.9%. (C) 2019 Optical Society of America
Flexible compact microdisk lasers on a polydimethylsiloxane (PDMS) substrate
(2009-01-19)
Shih, M. H.
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Hsu, S.
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Wang, Y. C.
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Yang, Y. C.
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Tsai, S. K.
Compact microdisk cavities were fabricated on a polydimethylsiloxane substrate. The lasing of the flexible compact cavity was achieved with a low threshold power. The whispering-gallery mode of the microdisk was also characterized with three-dimensional finite-difference time-domain simulation. The curvature dependence in output power and threshold was also demonstrated by bending the microdisk cavity. (C) 2008 Optical Society of America
Flexible compact microdisk lasers on a polydimethylsiloxane (PDMS) substrate
(2009-01-19)
Shih, M. H.
;
Hsu, S.
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Wang, Y. C.
;
Yang, Y. C.
;
Tsai, S. K.
Compact microdisk cavities were fabricated on a polydimethylsiloxane substrate. The lasing of the flexible compact cavity was achieved with a low threshold power. The whispering-gallery mode of the microdisk was also characterized with three-dimensional finite-difference time-domain simulation. The curvature dependence in output power and threshold was also demonstrated by bending the microdisk cavity. (C) 2008 Optical Society of America
Geometrical effect of bump resistance for flip-clip solder joints: Finite-element modeling and experimental results
(2006-08-01)
Liang, S. W.
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Chang, Y. W.
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Chen, Chih
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Liu, Y. C.
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Chen, K. H.
The bump resistance of flip-chip solder joints was measured experimentally and analyzed by the finite-element method. Kelvin structures for flip-chip solder joints were designed and fabricated to measure the bump resistance. The measured value was only about 0.9 m Omega at room temperature, which was much lower than that expected. Three-dimensional (3-D) modeling was performed to examine the current and voltage distribution in the joint. The simulated value was 7.7 m Omega, which was about 9 times larger than the experimental value. The current crowding effect was found to be responsible for the difference in bump resistance. Therefore, the measured bump resistance strongly depended on the layout of the Kelvin structure. Various layouts were simulated to investigate the geometrical effect of bump resistance, and a significant geometrical effect was found. A proper layout was proposed to measure the bump resistance correctly. The Kelvin structure would play an important role in monitoring void formation and microstructure changes during the electromigration of flip-chip solder joints.
High-power dual-color yellow-green solid-state self-Raman laser
(2019-07-01)
Chen, Y. F.
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Liu, Y. C.
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Gu, D. Y.
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Pan, Y. Y.
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Cheng, H. P.
A compact dual-color solid-state self-Raman laser with adjustable power-ratio between yellow and green emissions is demonstrated by using a specially coated Nd:YVO4 crystal. The Nd:YVO4 crystal is coated to replace a cavity mirror for minimizing the cavity losses and to reflect the backward green-yellow emission for avoiding the absorption. Two different lithium triborate (LBO) crystals are employed to produce the SHG of the 1176 nm Stokes field and the 1064 nm fundamental wave for the yellow and green emissions. The temperature of the LBO crystal for yellow generation is controlled at the optimal phase-matching to maximize the efficiency. The temperature of the LBO crystal for green generation is precisely varied to adjust the power-ratio between the yellow and green emissions. At the temperature for balanced emissions, both of 532 nm and 588 nm output powers can simultaneously achieve 4.0 W at a pump power of 31.6 W.