Browsing by Author "Wang, CL"

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A new type of saturable Bragg reflector with record-low saturation fluence and broad tuning range
(1998)
Shieh, JM
;
Huang, TC
;
Huang, KF
;
Wang, CL
;
Pan, CL
The saturation fluence for a strained triple-quantum-well saturable Bragg reflector was as low as 12 mu J/cm(2) Self-starting femtosecond pulses tunable from 768 to 804nm was realized.
A novel tunable dual-wavelength external-cavity laser diode array and its applications
(1996-10-01)
Pan, CL
;
Wang, CL
;
交大名義發表
;
光電工程學系
;
National Chiao Tung University
We review the principles and characteristics of a novel tunable external-cavity laser diode source. It can operate as either a continuous wave (CW) single-wavelength, a CW dual-wavelength, a single-wavelength mode-locked, or a tunable dual-wavelength mode-locked laser. The gain medium is a commercial laser diode array, The telescopic external cavity consists of a grazing-incidence grating, a lens and a stripe-mirror. The external cavity provides functions of wavelength selection, dispersion compensation and spatial mode control. The characteristics of the laser under CW or mode-locked operation are described. The dual-wavelength laser output exhibits beat note beyond 7 THz. The tunable multi-terahertz beat frequency is characterized by a non-collinear intensity autocorrelation technique. A dual-wavelength interferometer that uses a tunable dual-wavelength laser as the light source is demonstrated. Finally, theoretical analysis is presented, which demonstrates that the dual-wavelength output of the laser is stable if the modes at the two wavelengths correspond to different array lateral modes.
A novel tunable dual-wavelength external-cavity laser diode array and its applications
(1996-10-01)
Pan, CL
;
Wang, CL
;
光電工程研究所
;
Institute of EO Enginerring
We review the principles and characteristics of a novel tunable external-cavity laser diode source. It can operate as either a continuous wave (CW) single-wavelength, a CW dual-wavelength, a single-wavelength mode-locked, or a tunable dual-wavelength mode-locked laser. The gain medium is a commercial laser diode array, The telescopic external cavity consists of a grazing-incidence grating, a lens and a stripe-mirror. The external cavity provides functions of wavelength selection, dispersion compensation and spatial mode control. The characteristics of the laser under CW or mode-locked operation are described. The dual-wavelength laser output exhibits beat note beyond 7 THz. The tunable multi-terahertz beat frequency is characterized by a non-collinear intensity autocorrelation technique. A dual-wavelength interferometer that uses a tunable dual-wavelength laser as the light source is demonstrated. Finally, theoretical analysis is presented, which demonstrates that the dual-wavelength output of the laser is stable if the modes at the two wavelengths correspond to different array lateral modes.
A simple method for blocking parasitic modes in a waveguide-packaged microstrip-line circuit
(1998-12-01)
Chen, HH
;
Wang, CL
;
Chung, SJ
;
電信工程研究所
;
Institute of Communications Engineering
A simple structure formed by two metal patches symmetrically deposited at the two sides of the center microstrip is proposed and analyzed for blacking the higher order modes in a waveguide-packaged microstrip-line circuit. The variations (with the patch width) of the effective dielectric constants and field distributions of the modes in the packaged microstrip line with infinitely long side patches were first investigated using the two-dimensional (2-D) finite-element method (FEM) and the method of lines. The results suggested that there exists a range of patch widths at which the held distributions of the higher order modes are totally different from those of the microstrip line without side patches. The scattering of the patches as a function of the patch length and width was then studied using the three-dimensional (3-D) FEM with edge elements. It has been found that by simply choosing appropriate patch sizes, the parasitic higher order mode can be reflected without sacrificing the normal propagation of the dominant mode.
A simple method for blocking parasitic modes in a waveguide-packaged microstrip-line circuit
(1998-12-01)
Chen, HH
;
Wang, CL
;
Chung, SJ
;
電信工程研究所
;
Institute of Communications Engineering
A simple structure formed by two metal patches symmetrically deposited at the two sides of the center microstrip is proposed and analyzed for blacking the higher order modes in a waveguide-packaged microstrip-line circuit. The variations (with the patch width) of the effective dielectric constants and field distributions of the modes in the packaged microstrip line with infinitely long side patches were first investigated using the two-dimensional (2-D) finite-element method (FEM) and the method of lines. The results suggested that there exists a range of patch widths at which the held distributions of the higher order modes are totally different from those of the microstrip line without side patches. The scattering of the patches as a function of the patch length and width was then studied using the three-dimensional (3-D) FEM with edge elements. It has been found that by simply choosing appropriate patch sizes, the parasitic higher order mode can be reflected without sacrificing the normal propagation of the dominant mode.
Broadly tunable self-starting passively mode-locked Ti : sapphire laser with triple-strained quantum-well saturable Bragg reflector
(1998-11-01)
Shieh, JM
;
Huang, TC
;
Huang, KF
;
Wang, CL
;
Pan, CL
We demonstrate broadband mode-locking of femtosecond Ti:sapphire lasers with a new type of saturable Bragg reflector (SBR). Triple-strained quantum wells with separate and sequential bandgaps were used as the absorbing layer. The saturation fluence was as low as 7 mu J/cm(2). Self-starting sub-100 fs pulses tunable from 768 to 804 nm were generated in a standard X-folded cavity without intracavity tight focusing on the SBR or temperature tuning. The threshold fluence for self-starting mode-locking was 1 mu J/cm(2). (C) 1998 Elsevier Science B.V. All rights reserved.
Broadly tunable self-starting passively mode-locked Ti : sapphire laser with triple-strained quantum-well saturable Bragg reflector
(1998-11-01)
Shieh, JM
;
Huang, TC
;
Huang, KF
;
Wang, CL
;
Pan, CL
We demonstrate broadband mode-locking of femtosecond Ti:sapphire lasers with a new type of saturable Bragg reflector (SBR). Triple-strained quantum wells with separate and sequential bandgaps were used as the absorbing layer. The saturation fluence was as low as 7 mu J/cm(2). Self-starting sub-100 fs pulses tunable from 768 to 804 nm were generated in a standard X-folded cavity without intracavity tight focusing on the SBR or temperature tuning. The threshold fluence for self-starting mode-locking was 1 mu J/cm(2). (C) 1998 Elsevier Science B.V. All rights reserved.
In-place random list permutations
(1999-06-30)
Hwang, WP
;
Wang, CL
;
資訊工程學系
;
Department of Computer Science
We give two algorithms to randomly permute a linked list of length n in place using O(n log n) time and O(log n) stack space in both the expected case and the worst case. The first algorithm uses well-known sequential random sampling, and the second uses inverted sequential random sampling. (C) 1999 Published by Elsevier Science B.V. All rights reserved.
New insight into the degradation mechanism of nitride spacer with different post-oxide in submicron LDD n-MOSFET's
(1998-03-01)
Yih, CM
;
Wang, CL
;
Chung, SS
;
Wu, CC
;
Tan, W
In this paper, the hot carrier degradation mechanisms in lightly-doped drain (LDD) n-MOS devices with silicon nitride spacer have been investigated. A low temperature chemical vapor deposited (CVD) SiO2 oxide is used as a post-oxide between source/drain surface and the nitride spacer. The gated-diode measurement in combination with the gate-induced drain leakage (GIDL) current measurement techniques have been used to analyze the stress-induced interface state and oxide charges. For the first time, it was found that the oxide charge but not the interface state generation in the post oxide will dominate the device drain current degradation. Moreover, the CVD post oxide with N-2 annealing has been proposed which is able to effectively suppress the generation of oxide charges and significantly improve the device hot carrier reliability. The scaling of gate oxide thickness and the optimization of source/drain junction to improve the device reliability are also demonstrated.