Search Results - (Author, Cooperation:Y. H. Lo)
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1Latest Papers from Table of Contents or Articles in PressC. A. Lindemans ; M. Calafiore ; A. M. Mertelsmann ; M. H. O'Connor ; J. A. Dudakov ; R. R. Jenq ; E. Velardi ; L. F. Young ; O. M. Smith ; G. Lawrence ; J. A. Ivanov ; Y. Y. Fu ; S. Takashima ; G. Hua ; M. L. Martin ; K. P. O'Rourke ; Y. H. Lo ; M. Mokry ; M. Romera-Hernandez ; T. Cupedo ; L. E. Dow ; E. E. Nieuwenhuis ; N. F. Shroyer ; C. Liu ; R. Kolesnick ; M. R. van den Brink ; A. M. Hanash
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-12-10Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Epithelial Cells/*cytology/immunology/pathology ; Female ; Graft vs Host Disease/pathology ; Humans ; Immunity, Mucosal ; Interleukins/deficiency/*immunology ; Intestinal Mucosa/*cytology/immunology/pathology ; Intestine, Small/*cytology/immunology/pathology ; Mice ; Organoids/cytology/growth & development/immunology ; Paneth Cells/cytology ; Phosphorylation ; *Regeneration ; STAT3 Transcription Factor/metabolism ; Signal Transduction ; Stem Cell Niche ; Stem Cells/*cytology/*metabolismPublished by: -
2Latest Papers from Table of Contents or Articles in PressChiou, W.-Y., Lee, M.-S., Hung, S.-K., Lin, H.-Y., Lo, Y.-C., Hsu, F.-C., Tsai, S.-J., Li, C.-Y.
BMJ Publishing
Published 2018Staff ViewPublication Date: 2018-05-17Publisher: BMJ PublishingElectronic ISSN: 2044-6055Topics: MedicineKeywords: Open access, Public healthPublished by: -
3Latest Papers from Table of Contents or Articles in PressH. Y. Lo ; D. Kienzler ; L. de Clercq ; M. Marinelli ; V. Negnevitsky ; B. C. Keitch ; J. P. Home
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-05-23Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsPublished by: -
4Latest Papers from Table of Contents or Articles in PressD. Kienzler ; H. Y. Lo ; B. Keitch ; L. de Clercq ; F. Leupold ; F. Lindenfelser ; M. Marinelli ; V. Negnevitsky ; J. P. Home
American Association for the Advancement of Science (AAAS)
Published 2014Staff ViewPublication Date: 2014-12-20Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
5Latest Papers from Table of Contents or Articles in PressDeng, J., Lo, Y. H., Gallagher-Jones, M., Chen, S., Pryor, A., Jin, Q., Hong, Y. P., Nashed, Y. S. G., Vogt, S., Miao, J., Jacobsen, C.
American Association for the Advancement of Science (AAAS)
Published 2018Staff ViewPublication Date: 2018-11-03Publisher: American Association for the Advancement of Science (AAAS)Electronic ISSN: 2375-2548Topics: Natural Sciences in GeneralPublished by: -
6Articles: DFG German National LicensesLee, H. P. ; Vakhshoori, D. ; Lo, Y. H. ; Wang, Shyh
[S.l.] : American Institute of Physics (AIP)
Published 1985Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: A theoretical model of electron temperature and electron mobility as a function of electric field has been formulated for GaAs/AlxGa1−xAs heterostructures. The predicted results from this model agree well with available measurements at low and moderate fields (E〉200 V/cm). Furthermore, this model enables us to predict the electron temperature and mobility at high fields which are crucial to the understanding of the potential performance of GaAs/AlxGa1−xAs modulation-doped field effect transistor and other novel heterostructures.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesLo, Y. H. ; Bhat, R. ; Hwang, D. M. ; Koza, M. A. ; Lee, T. P.
Woodbury, NY : American Institute of Physics (AIP)
Published 1991Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: A technique, namely bonding by atomic rearrangement has been invented to realize high quality heteroepitaxy for lasers and optoelectronics. High performance lasers of 1.5 μm wavelength have been fabricated on GaAs substrates using this method. The laser has the same threshold current and quantum efficiency as lasers on InP substrates. No performance degradation has been observed. The transmission electron microscopic results show that the heteroepitaxy is excellent, without a single threading dislocation or stacking fault.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaff View
ISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: A multilayer structure for thermionic cooling is proposed. This structure uses semiconductor heterojunctions for barriers and a varying current density across the junctions. Compared with the conventional multijunction thermionic cooler with a uniform current density, the design can yield a significantly higher temperature gradient, thus cooling more effectively. © 1999 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesZhou, Y. C. ; Zhu, Z. H. ; Crouse, D. ; Lo, Y. H.
Woodbury, NY : American Institute of Physics (AIP)
Published 1998Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: This letter reports on the fabrication and electrical characterization of wafer-fused GaAs/Si heterojunctions. A detailed study of the effect of surface preparation on bonding GaAs to Si was performed. The current–voltage (I–V) characteristics of both n-GaAs/n-Si and p-GaAs/p-Si were measured from 77 K to room temperature. The forward I–V characteristics were analyzed using a numerical model that includes thermionic emission across the heterojunction. Specifically, a p-GaAs/p-Si heterointerface of high electrical quality was obtained by direct hydrophobic bonding. © 1998 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesZhu, Z. H. ; Zhou, R. ; Ejeckam, F. E. ; Zhang, Z. ; Zhang, J. ; Greenberg, J. ; Lo, Y. H.
Woodbury, NY : American Institute of Physics (AIP)
Published 1998Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: InGaAs multiple quantum wells at 1.3 μm wavelength have been grown on a twist-bonded GaAs compliant substrate. The GaAs compliant substrate contains a 30 Å GaAs thin layer bonded to a GaAs bulk substrate with a 22-degree angle. Nomarski phase contrast microscopy, transmission electron microscopy (TEM), and photoluminescence were used to characterize the heteroepitaxial layers. The smooth and crosshatch-free surface morphology, dislocation-free cross-sectional TEM, and strong luminescence intensity all provide convincing evidences for substantial improvement of the quality of heteroepitaxial material using the compliant substrate technique. Research is underway to apply the concept and technique of compliant substrate to Si and other materials. © 1998 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesStaff View
ISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We proposed and demonstrated a novel design for long wavelength (1.3 μm) vertical-cavity surface-emitting lasers (VCSELs). In this design, oxygen-implanted current-confinement regions were formed in a GaAs/AlGaAs Bragg reflector which is the bottom mirror wafer bonded to an AlGaInAs/InP cavity consisting of nine strain-compensated quantum wells. Room- temperature continuous-wave (cw) operation of 1.3 μm-VCSELs with a record low cw threshold current density of 1.57 kA/cm2 and a record low cw threshold current of 1 mA have been realized. © 1997 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesEjeckam, F. E. ; Chua, C. L. ; Zhu, Z. H. ; Lo, Y. H. ; Hong, M. ; Bhat, R.
Woodbury, NY : American Institute of Physics (AIP)
Published 1995Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: In this work, we demonstrate record low dark current operation of InGaAs (1.55 μm) p-i-n photodetectors on both silicon and gallium arsenide substrates using a wafer bonding technique. The photodetectors were made by first bonding the p-i-n epitaxial layers to the Si and GaAs substrate followed by chemical removal of the host (InP) substrate from the p-i-n structure. The photodetector was then fabricated atop the newly exposed p-i-n epilayers. Dark currents of as low as 57 pA on a GaAs substrate and 0.29 nA on a Si substrate were measured under 5 V reverse bias. The responsivity at 1.55 μm wavelength was measured to be 1 A/W, corresponding to an external quantum efficiency of 80%. The series resistance measured across the bonded interface gave 17 Ω on GaAs and 350 Ω on Si, respectively. © 1995 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesLo, Y. H. ; Wu, M. C. ; Lee, H. ; Wang, S. ; Liliental-Weber, Z.
Woodbury, NY : American Institute of Physics (AIP)
Published 1988Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: Type-I dislocations at the GaAs/Si interface are beneficial because they effectively relax the mismatched stress, but do not propagate into the GaAs film. Accordingly, the best way to grow a low defect density GaAs film on a Si substrate is to form as many as possible type-I dislocations or, equivalently, to suppress other kinds of defects. The high-resolution transmission electron microscopy study shows that most of the type-I dislocations are formed at the double step on a Si surface. It is further determined that the silicon surface steps are mainly due to the substrate tilting instead of the heating before growth. Based on our study, the (100) Si substrate with double steps along both [110] and [11¯0] axes provides the best condition for growing low defect density GaAs on Si substrates.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesLo, Y. H. ; Deri, R. J. ; Harbison, J. ; Skromme, B. J. ; Seto, M. ; Hwang, D. M. ; Lee, T. P.
Woodbury, NY : American Institute of Physics (AIP)
Published 1988Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: The GaAs-on-InP heteroepitaxial waveguides are demonstrated for the first time using molecular beam epitaxy. A propagation loss of 9.3 dB/cm was obtained for waveguides grown on a 3° off (100) InP substrate. Compared to the 16 dB/cm loss for waveguides on (100) InP substrates, the waveguides on misoriented InP substrates exhibited a significantly lower loss. Based on photoluminescence studies, we attribute the propagation loss in both samples mainly to optical absorption by crystal defects. Defect densities of 4×1017 cm−3 and 2×1017 cm−3 are estimated for material on (100) and 3° off (100) substrates, respectively. Such heteroepitaxial waveguides may have applications in long-wavelength photonic integrated circuits.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesChang-Hasnain, C. J. ; Lo, Y. H. ; Bhat, R. ; Stoffel, N. G. ; Lee, T. P.
Woodbury, NY : American Institute of Physics (AIP)
Published 1989Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: High quality GaAs quantum well lasers grown on (100) and 3°-off (100)InP substrates by organometallic chemical vapor deposition were investigated for the first time. 50-μm-wide broad-area gain-guided lasers were fabricated using preferential proton implantation. Low threshold densities, 800 and 1080 A/cm2, were obtained at room temperature for lasers with 1.25-mm-long cavities grown on 3°-off (100) and (100) oriented InP substrates, respectively. High quantum efficiency of 36% and nearly single longitudinal mode emission were also achieved from these lasers.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesWu, M. C. ; Boenke, M. M. ; Werner, M. ; Schiffmann, F. ; Lo, Y. H. ; Wang, S.
[S.l.] : American Institute of Physics (AIP)
Published 1988Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: We present a theoretical analysis of a newly demonstrated semiconductor laser with coupled distributed feedback and Fabry–Perot (DFB-FP) cavities and show that three modes of operation are possible for such a laser. In mode-switched DFB mode, the wavelength can be switched between longitudinal modes on either side of the stopband. In coupled-cavity laser mode, there are successive mode hops inside the stopband. Finally, in continuously tunable distributed Bragg reflector mode, a wide wavelength tuning range (4.8 A(ring)) without mode hopping can be obtained. The analysis is general enough to be applied to any laser with a periodic waveguide section, and provides an understanding of the mechanisms and the limits of wavelength tuning in such lasers. This type of laser has very important applications in coherent optical communications.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesZhu, Z. H. ; Wu, M. C. ; Lo, Y. H. ; Pan, C. L. ; Wang, S. Y. ; Wang, S.
[S.l.] : American Institute of Physics (AIP)
Published 1988Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: We report the experimental results of the standing waves in GaAs coplanar waveguides at frequencies up to 20.10 GHz with different terminations (open, short, and 50 Ω) by a new electro-optic probing technique. The effective refractive indices from 4.11 to 20.10 GHz are presented and compared with theoretical values. Dispersion of coplanar waveguide in that frequency range is shown to be negligible.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesLin, C. H. ; Chua, C. L. ; Zhu, Z. H. ; Lo, Y. H.
Woodbury, NY : American Institute of Physics (AIP)
Published 1994Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: Optical gain distribution among quantum wells for (strained) multiple-quantum well (MQW) lasers was analyzed to understand the effect of nonuniform pumping. The nonuniform gain distribution is mainly caused by stagnant hole transport across the quantum wells. Contrary to what people expected, neither uniformly p-doped MQWs nor selectively p-doped MQWs can alleviate the nonuniform pumping problem. The most effective solution is employing an exponential p-doping profile which can counterbalance the nonuniform injection effect. Our simulation results showed that such an exponential p-doping profile has a characteristic length around one-half of the ambipolar diffusion length. © 1994 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesTeng, D. ; Lo, Y. H. ; Lin, C. H. ; Eastman, L. F.
Woodbury, NY : American Institute of Physics (AIP)
Published 1992Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We theoretically investigate the effects of nonuniform well widths on compressively strained In0.2Ga0.8As/GaAs multiple quantum well lasers using multiband effective mass theory and density matrix formalism. We find that the well width fluctuations do not degrade the transparency current, differential gain, and linewidth broadening factor. Besides, lasers with intentionally designed chirped well width have much broader gain profiles compared to uniform well lasers. This feature is attractive for applications requiring large gain bandwidth such as tunable lasers, mode-locked lasers, and wavelength division multiplexed laser arrays.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesChua, C. L. ; Hsu, W. Y. ; Lin, C. H. ; Christenson, G. ; Lo, Y. H.
Woodbury, NY : American Institute of Physics (AIP)
Published 1994Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We demonstrated the high-quality molecular beam epitaxy growth of exceedingly thick In0.14Ga0.86As pseudomorphic layers on thin, free-standing, compliant GaAs substrates. We first fabricated 800-A(ring)-thick compliant platforms before growing a lattice-mismatched layer on the platform. The layer we grew exceeds its usual critical thickness by about twenty times without strain relaxation. X-ray analysis confirms a shift in the InGaAs peaks grown on the compliant substrate, indicating an unrelaxed strain of 0.9%. Moreover, atomic force microscope profiles verify that layers grown on compliant substrates are much smoother than layers grown on a plain substrate.Type of Medium: Electronic ResourceURL: