Studies on first GaN-based blue-violet laser diodes(LDs) in China mainland are reported.High quality GaN materials as well as GaN-based quantum wells laser structures are grown by metal-organic chemical vapor depositi...Studies on first GaN-based blue-violet laser diodes(LDs) in China mainland are reported.High quality GaN materials as well as GaN-based quantum wells laser structures are grown by metal-organic chemical vapor deposition method.The X-ray double-crystal diffraction rocking curve measurements show the full-width half maximum of 180″ and 185″ for (0002) symmetric reflection and (10 12) skew reflection,respectively.A room temperature mobility of 850cm2/(V·s) is obtained for a 3μm thick GaN film.Gain guided and ridge geometry waveguide laser diodes are fabricated with cleaved facet mirrors at room temperature under pulse current injection.The lasing wavelength is 405 9nm.A threshold current density of 5kA/cm2 and an output light power over 100mW are obtained for ridge geometry waveguide laser diodes.展开更多
TN248.4 2003020959980nm半导体激光器远场特性的优化=Optimization offar field properties for 980 nm semiconductor lasers[刊,中]/邹德恕(北京工业大学光电子技术实验室.北京(100022)),廉鹏…//半导体光电.-2002,23(4).-259-261制...TN248.4 2003020959980nm半导体激光器远场特性的优化=Optimization offar field properties for 980 nm semiconductor lasers[刊,中]/邹德恕(北京工业大学光电子技术实验室.北京(100022)),廉鹏…//半导体光电.-2002,23(4).-259-261制作小功率半导体激光器时,为了减小阈值电流,提高斜率效率,一般都采用深腐蚀法形成脊形结构以克服电流横向扩展。但是由于工艺的原因,往往使得激光器远场特性恶化,特别是水平发散角θ_∥形式多瓣。研究发现这与光刻工艺有着重要关系,利用自对准自然解理边形成TiAu欧姆接触方法克服了上述现象。展开更多
Olfactory ensheathing cells(OECs) transplanted into the damaged spinal cord may be considered as a valuable remedy explorations for spinal cord repair. The proliferation of transplanted olfactory ensheathing cells dep...Olfactory ensheathing cells(OECs) transplanted into the damaged spinal cord may be considered as a valuable remedy explorations for spinal cord repair. The proliferation of transplanted olfactory ensheathing cells depends on various environmental factors and effective cues, which may include electrical fields(EFs). In this study, we investigated the proliferative capacity, morphologic alterations of olfactory ensheathing cells derived from neonate rat that occurd when exposed to two EFs of 20 Hz, 50 mV and20 Hz, 100 mV for 6 h. For both EF treatments, the MTT results revealed that the cellular proliferation of exposed group during the last 6 h of the experiment was statistically higher than that of control group. Then, we investigated morphological structure changes in the cells stained by Coomassie brilliant blue. Compared with control group, most of cells were present at intensively proliferating appearance including the microfilaments were long and thick and the accumulated appearance of cells. It is conceivable that electrical fields as a new approach may promote the growth and proliferation of OECs and may be engineered to control the survival of transplanted OECs in injured spinal cord.Although our results have been suggesting that EFs may be non-chemical strategies for cell proliferation, the fundamental mechanisms remain to be elucidated.展开更多
文摘Studies on first GaN-based blue-violet laser diodes(LDs) in China mainland are reported.High quality GaN materials as well as GaN-based quantum wells laser structures are grown by metal-organic chemical vapor deposition method.The X-ray double-crystal diffraction rocking curve measurements show the full-width half maximum of 180″ and 185″ for (0002) symmetric reflection and (10 12) skew reflection,respectively.A room temperature mobility of 850cm2/(V·s) is obtained for a 3μm thick GaN film.Gain guided and ridge geometry waveguide laser diodes are fabricated with cleaved facet mirrors at room temperature under pulse current injection.The lasing wavelength is 405 9nm.A threshold current density of 5kA/cm2 and an output light power over 100mW are obtained for ridge geometry waveguide laser diodes.
文摘TN248.4 2003020959980nm半导体激光器远场特性的优化=Optimization offar field properties for 980 nm semiconductor lasers[刊,中]/邹德恕(北京工业大学光电子技术实验室.北京(100022)),廉鹏…//半导体光电.-2002,23(4).-259-261制作小功率半导体激光器时,为了减小阈值电流,提高斜率效率,一般都采用深腐蚀法形成脊形结构以克服电流横向扩展。但是由于工艺的原因,往往使得激光器远场特性恶化,特别是水平发散角θ_∥形式多瓣。研究发现这与光刻工艺有着重要关系,利用自对准自然解理边形成TiAu欧姆接触方法克服了上述现象。
文摘Olfactory ensheathing cells(OECs) transplanted into the damaged spinal cord may be considered as a valuable remedy explorations for spinal cord repair. The proliferation of transplanted olfactory ensheathing cells depends on various environmental factors and effective cues, which may include electrical fields(EFs). In this study, we investigated the proliferative capacity, morphologic alterations of olfactory ensheathing cells derived from neonate rat that occurd when exposed to two EFs of 20 Hz, 50 mV and20 Hz, 100 mV for 6 h. For both EF treatments, the MTT results revealed that the cellular proliferation of exposed group during the last 6 h of the experiment was statistically higher than that of control group. Then, we investigated morphological structure changes in the cells stained by Coomassie brilliant blue. Compared with control group, most of cells were present at intensively proliferating appearance including the microfilaments were long and thick and the accumulated appearance of cells. It is conceivable that electrical fields as a new approach may promote the growth and proliferation of OECs and may be engineered to control the survival of transplanted OECs in injured spinal cord.Although our results have been suggesting that EFs may be non-chemical strategies for cell proliferation, the fundamental mechanisms remain to be elucidated.
