An extra-short He-Ne laser (shorter than 100mm) does not work well because there is likely no longitudinal mode in the lasing bandwidth sometimes and the output power rises and falls deeply from time to time.A method ...An extra-short He-Ne laser (shorter than 100mm) does not work well because there is likely no longitudinal mode in the lasing bandwidth sometimes and the output power rises and falls deeply from time to time.A method to solve this problem has been presented and investigated.A piece of quartz crystal plate appropriately designed is used as a cavity mirror of a He-Ne laser,which has a longitudinal mode spacing larger than the lasing bandwidth to make the equal-spacing mode split.In other words,the number of longitudinal modes is doubled and the actual mode spacing is reduced to the half of that without mode split.Therefore,there is always at least one mode operating in the lasing bandwidth and the power is stable at any room temperature.Such a laser with 85mm cavity length and 0.24mW output power has been made.展开更多
介绍了辽宁电网安全稳定方面存在的主要问题,辽宁中长期特高压和500 k V电网规划情况及目前辽宁电网分区运行情况。基于搭建的电力系统仿真软件PSD-BPA数据库,计算辽宁电网短路电流水平,针对短路电流超标的地区给出解决方案。结合为降...介绍了辽宁电网安全稳定方面存在的主要问题,辽宁中长期特高压和500 k V电网规划情况及目前辽宁电网分区运行情况。基于搭建的电力系统仿真软件PSD-BPA数据库,计算辽宁电网短路电流水平,针对短路电流超标的地区给出解决方案。结合为降低短路电流水平而实施的线路解环情况,2020年底辽宁电网将形成15个供电分区。就短路电流超标问题,给出了趋势性的建议。展开更多
基金Project supported by the Natural Science Foundation of Beijing.
文摘An extra-short He-Ne laser (shorter than 100mm) does not work well because there is likely no longitudinal mode in the lasing bandwidth sometimes and the output power rises and falls deeply from time to time.A method to solve this problem has been presented and investigated.A piece of quartz crystal plate appropriately designed is used as a cavity mirror of a He-Ne laser,which has a longitudinal mode spacing larger than the lasing bandwidth to make the equal-spacing mode split.In other words,the number of longitudinal modes is doubled and the actual mode spacing is reduced to the half of that without mode split.Therefore,there is always at least one mode operating in the lasing bandwidth and the power is stable at any room temperature.Such a laser with 85mm cavity length and 0.24mW output power has been made.
文摘介绍了辽宁电网安全稳定方面存在的主要问题,辽宁中长期特高压和500 k V电网规划情况及目前辽宁电网分区运行情况。基于搭建的电力系统仿真软件PSD-BPA数据库,计算辽宁电网短路电流水平,针对短路电流超标的地区给出解决方案。结合为降低短路电流水平而实施的线路解环情况,2020年底辽宁电网将形成15个供电分区。就短路电流超标问题,给出了趋势性的建议。
