Browsing by Author "Huang, KF"

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A fully all-planar integrated Ka-band FSK transceiver module
(2001)
Lee, CJ
;
Hung, TP
;
Lin, SC
;
Wu, HS
;
Tsai, CY
An open RFIC (Radio Frequency Integrated Circuit) architecture employing ACSS (Advanced Coplanar Strips System) guiding technology is presented in this paper. This approach can integrate all the RF front-end components in one module using conventional PCB (printed circuit board) fabrication process. A 10 Mb/s FSK signal is upconverted to 30.18 GHz and 30.28 GHz and broadcasted through a cone-shaped antenna at power level of 10 dBm. The received signal is directly converted to baseband by even harmonic quadrature mixer, which shows a great isolation of 30 dB between RF and LO signal. The measured waveforms of the reported transceiver demonstrate the potential of constructing the wireless system with all-planar integrated circuits.
A new category of semiconductor nonlinear mirrors for ultrafast pulse generation and switching
(2001)
Pan, CL
;
Liu, TA
;
Shieh, JM
;
Huang, KF
;
光電工程學系
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.
Alterable temperature-dependent wavelength shifts in (InP)(2)/(GaP)(2) quantum wells
(1998-02-02)
Cheng, YC
;
Tai, K
;
Chou, ST
;
Huang, KF
;
Tu, SL
Alterable temperature-dependent emission wavelength shifts were observed from (InP)(2)/(GaP)(2) short-period superlattices (SPSs) quantum wells grown with different interruption periods. Photoluminescence spectra showed that the peak energy of the SPS samples is inversely proportional to the interruption time conducted between the two consecutive binary growth sequences in the SPS regions. It is believed that a lateral composition modulation occurred during the interruption period which resulted in periodic In-rich and Ga-rich regions in the SPS quantum wells along the growth plane. With the lateral compositional variation, temperature variation can induce a multiaxial strain effect which can either amplify or reduce the temperature-dependent wavelength shift of the SPS quantum wells with different interruption periods. (C) 1998 American Institute of Physics.
AuBe Ohmic contacts to p-type ZnTe
(1998-12-10)
Lan, WH
;
Lin, WJ
;
Cheng, YC
;
Tai, K
;
Tasi, CM
Ohmic contacts of AuBe to p-ZnTe show a minimum specific contact resistance of 3.0 x 10(-6) Ohm cm(2) for a p-doping level of 1.6 x 10(19) cm(-3) and at an annealing temperature of 200 degrees C. The beryllium is very effective at improving the electrical properties of p-type contacts to ZnTe.
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.
Comment on "Formation of repetitively nanosecond spatial solitons in a saturable absorber Q-switched laser" - Reply
(2005-06-24)
Chen, YF
;
Huang, KF
;
電子物理學系
;
Department of Electrophysics
Critical point energy as a function of electric field determined by electroreflectance of surface-intrinsic-n(+) type doped GaAs
(2004-11-01)
Chen, YS
;
Wu, KS
;
Wang, DP
;
Huang, KF
;
Huang, TC
Electroreflectance of surface-intrinsic-n(+) type doped GaAs has been measured over a various biased voltage. The spectra have exhibited many Franz-Keldysh oscillations (FKOs) above band gap energy E-g. The electric field F and critical point energy E-c can be determined from the slope and intercept of FKOs fitting. Hence, we can obtain E-c as a function of F. In most of previous works, E-c is taken as E-g. However, it was found that E-c increases with F in this work. In order to explain this, the gain of energy of electron and hole in F was discussed. (C) 2004 American Institute of Physics.
Deep electron trapping centers in Te-doped (AlxGa1-x)(0.5)In0.5P (x=0.5) layers grown by metal-organic chemical vapor deposition
(2002-06-01)
Sung, WJ
;
Huang, KF
;
Tseng, TY
;
電子物理學系
;
Department of Electrophysics
The properties of deep electron trapping centers of Te-doped (AlxGa1-x)(0.5)In0.5P (x = 0.5) layers grown by metal-organic chemical vapor deposition (MOCVD) are studied by using deep level transient spectroscopy (DLTS) technique. One distinct deep electron trap located at 0.165 +/- 0.01 eV is observed and found to increase as elevating Te-dopant concentration in (AlxGa1-x)(0.5)In0.5P (,v = 0.5) materials, indicating that this deep electron trap is a donor-related defect and has the similar characters as deep levels observed in Si- and Se-doped (AlxGa1-x)(0.5)In0.5P.
Deep hole traps created by gamma-ray irradiation of GaInP
(2001-12-01)
Sung, WJ
;
Liu, TY
;
Yang, SL
;
Huang, KF
;
Tseng, TY
Deep hole traps, created by gamma-ray irradiation of Al/GaInP Schottky diodes grown by metal-organic chemical vapor deposition (MOCVD) were studied by using deep level transient spectroscopy (DLTS) technique. Two distinct deep hole traps, A and B, were observed in the irradiated GaInP samples, According to the analysis of trap concentration in various samples, the trap A is verified as a bulk defect located at 0.29 eV above the valance band. Meanwhile, the trap B is an interface state originated from the junctions of Al/Mg-doped GaInP contacts.
Determination of built-in field by applying fast Fourier transform to the photoreflectance of surface-intrinsic n(+)-type doped GaAs
(1999-01-18)
Wang, DP
;
Wang, KR
;
Huang, KF
;
Huang, TC
;
Chu, AK
Photoreflectance spectroscopy of surface-intrinsic n(+)-doped (s-i-n(+)) GaAs has been measured at various power densities (P-pu) of a pump beam. Many Franz-Keldysh oscillations (FKOs) were observed above the band-gap energy, which will enable the electric-field strength (F) to be determined from the periods of the FKOs. Field F thus obtained is subject to photovoltaic effects. In order to reduce the photovoltaic effects from the pump beam, P-pu was kept below 10 mu W/cm(2) in the previous experiments. Here, we demonstrate that the built-in field can be determined at a larger P-pu by using fast Fourier transform techniques. (C) 1999 American Institute of Physics. [S0003-6951(99)02803-X].
Devil's staircase in three-dimensional coherent waves localized on Lissajous parametric surfaces
(2006-06-02)
Chen, YF
;
Lu, TH
;
Su, KW
;
Huang, KF
;
電子物理學系
We experimentally demonstrate the significance of the longitudinal-transverse coupling in the mesoscopic regime by using a high-Q laser resonator as an analog experiment. The longitudinal-transverse coupling is found to lead to the three-dimensional (3D) coherent waves that are localized on the parametric surfaces with Lissajous transverse patterns. More strikingly, experimental results reveal that the mode locking of the 3D coherent states forms a nearly complete Devil's staircase with the hierarchical ordering.
Diode-end-pumped passively mode-locked high-power Nd : YVO4 laser with a relaxed saturable Bragg reflector
(2001-02-15)
Chen, YF
;
Tsai, SW
;
Lan, YP
;
Wang, SC
;
Huang, KF
We demonstrate a high-power passively mode-locked Nd:YVO4 laser that uses a saturable Bragg reflector (SBR) with strain relaxation. 23.5 W of average power with similar to 21.5-ps cw mode-locked pulse trains was generated at a 50-W pump power. Experimental results show that appropriate strain relaxation in the SBR makes the mode-locking operation less sensitive to temperature variation. (C) 2001 Optical Society of America OCIS codes: 140.3530, 140.3580, 140.4050, 140.7090, 160.6000.
Diode-pumped passively mode-locked multiwatt Nd : GdVO4 laser with a saturable Bragg reflector
(2003-09-20)
He, JL
;
Lee, CK
;
Huang, JYJ
;
Wang, SC
;
Pan, CL
We report a first demonstration, to our knowledge, of a cw passively mode-locked Nd:GdVO4 laser (lambda = 1063 nm). A relaxed saturable Bragg reflector was used. The laser generates pulses of 9.2 ps at a repetition rate of 119 MHz. As much as 5.4 W of average power was realized with a slope efficiency of 25.7%. (C) 2003 Optical Society of America.
Effect of modulating field on photoreflectance simulated by electroreflectance
(1999-04-01)
Chiou, SJ
;
Sung, YG
;
Wang, DP
;
Huang, KF
;
Huang, TC
Photoreflectance (PR) of surface-intrinsic- n(+) (s-i-n(+)) type doped GaAs has been simulated by electroreflectance (ER). The simulated spectra of the s-i-n(+) sample have exhibited many Franz-Keldysh oscillations, which enable the electric field (F) to be determined. It is known that F's determined from PR are subjected to photovoltaic effect and the measured F is close to F-bi -delta F/2 when the modulating field, delta F much less than F-bi, where F-bi is the built- in field of the sample and delta F is the modulating field. In this work, we have investigated the relation between the measured F and delta F not only for the region where delta F much less than F bi holds, but also for a whole range of delta F. In order to determine the magnitude of dF, we have used ER to simulate PR, that is, the measurements of ER under a forward bias, which is set to be equal to delta F/2. (C) 1999 American Institute of Physics. [S0021-8979(99)01906-4].
Effects of polarization on electroreflectance spectroscopy of surface-intrinsic n(+)-type doped GaAs
(2002-01-01)
Sung, YG
;
Chiou, SJ
;
Wang, DP
;
Lu, YT
;
Huang, KF
The electroreflectance (ER) spectra of a surface-intrinsic n(+)-type doped (100) GaAs have been measured at various polarization angles of the probe beam. Several Franz-Keldysh oscillations were observed above the band-gap energy, thus enabling heavy- and light-hole transitions to be separated by the application of the fast Fourier transform to the ER spectra. From this, the ratios of the amplitudes of the light- to heavy-hole transitions versus angle of polarization were obtained. At a large incident angle (80 degrees), the strength of the field of the probe beam in the normal direction of the sample (F(z)) was varied from zero to a larger component. It was found that the ratios increased with increasing F(z) which is consistent with the theory that the light-hole transition becomes more enhanced with z-polarized light. (C) 2002 American Institute of Physics.
Efficient terahertz radiation generation from a bulk InAs mirror as an intracavity terahertz radiation emitter
(2000-04-15)
Liu, ZL
;
Ono, S
;
Ohtake, H
;
Sarukura, N
;
Liu, TA
Terahertz (THz) radiation is generated efficiently from a bulk InAs mirror with a shallow incidence angle inside the cavity of a femtosecond, mode-locked Ti:sapphire laser self-started by a strained saturable Bragg reflector A magnetic field is also applied to the InAs mirror to enhance THz radiation.
Electroreflectance of surface-intrinsic- n(+)-type doped GaAs
(1997-09-15)
Wang, DP
;
Huang, KM
;
Shen, TL
;
Huang, KF
;
Huang, TC
The electroreflectance spectra of surface-intrinsic-n(+)-type-doped GaAs were measured at various bias voltages (V-bias). Results revealed many Franz-Keldysh oscillations (FKOs) above the band-gap energy, which have been attributed to a uniform electric field (F) in the undoped layer below the surface. However, there has been no other evidence for the uniformity of F in the undoped layer. Since it is known that F can be deduced from the periods of the FKOs, the relations between F and V-bias can, thereby, be obtained. The nearly linear relation, thus found, confirms the existence of a nearly uniform field in the undoped layer. From the plot of F against V-bias,the Values of the thickness of the undoped layer and the barrier height can also be evaluated. (C) 1997 American Institute of Physics.
Electroreflectance of surface-intrinsic- n(+)-type doped GaAs
(1997-09-15)
Wang, DP
;
Huang, KM
;
Shen, TL
;
Huang, KF
;
Huang, TC
The electroreflectance spectra of surface-intrinsic-n(+)-type-doped GaAs were measured at various bias voltages (V-bias). Results revealed many Franz-Keldysh oscillations (FKOs) above the band-gap energy, which have been attributed to a uniform electric field (F) in the undoped layer below the surface. However, there has been no other evidence for the uniformity of F in the undoped layer. Since it is known that F can be deduced from the periods of the FKOs, the relations between F and V-bias can, thereby, be obtained. The nearly linear relation, thus found, confirms the existence of a nearly uniform field in the undoped layer. From the plot of F against V-bias,the Values of the thickness of the undoped layer and the barrier height can also be evaluated. (C) 1997 American Institute of Physics.