TN247 2005053370 光栅衍射法实时测量脉冲激光波长和方向=Measurement of pulsed-laser wavelength and direction in real time by grating diffraction method[刊,中]／付林(中北大学仪器科 学与动态测试教育部重点实验室．山西,太原...TN247 2005053370 光栅衍射法实时测量脉冲激光波长和方向=Measurement of pulsed-laser wavelength and direction in real time by grating diffraction method[刊,中]／付林(中北大学仪器科 学与动态测试教育部重点实验室．山西,太原(030051)), 张记龙…∥光电工程．-2005,32(7)．-30～32。展开更多
Using photonic crystals (PCs), the extraction efficiency of the light-emitting diodes (LEDs) can be greatly enhanced by the effects of photonic band gap (PBG) and grating diffraction. The two theoretical methods are a...Using photonic crystals (PCs), the extraction efficiency of the light-emitting diodes (LEDs) can be greatly enhanced by the effects of photonic band gap (PBG) and grating diffraction. The two theoretical methods are also discussed. Meanwhile, we demonstrate that LEDs can achieve high extraction efficiency by employing photonic crystal as diffraction grating. PCs with square lattice of cylindrical unit cells are fabricated in GaN layer of GaN-based blue LED. We present a theoretical discussion on the extraction efficiency of PC-LED, which relies on the effective medium theory and transmission matrix method to investigate the effect of lattice constant. The results show that the extraction efficiency of the high performance LEDs can achieve 61.8% when the lattice constant is 270 nm.展开更多
文摘TN247 2005053370 光栅衍射法实时测量脉冲激光波长和方向=Measurement of pulsed-laser wavelength and direction in real time by grating diffraction method[刊,中]／付林(中北大学仪器科 学与动态测试教育部重点实验室．山西,太原(030051)), 张记龙…∥光电工程．-2005,32(7)．-30～32。
基金supported by the National Natural Science Foundation of China (No.60877047)the Natural Science Foundation of Hebei Province (No.2010002002)
文摘Using photonic crystals (PCs), the extraction efficiency of the light-emitting diodes (LEDs) can be greatly enhanced by the effects of photonic band gap (PBG) and grating diffraction. The two theoretical methods are also discussed. Meanwhile, we demonstrate that LEDs can achieve high extraction efficiency by employing photonic crystal as diffraction grating. PCs with square lattice of cylindrical unit cells are fabricated in GaN layer of GaN-based blue LED. We present a theoretical discussion on the extraction efficiency of PC-LED, which relies on the effective medium theory and transmission matrix method to investigate the effect of lattice constant. The results show that the extraction efficiency of the high performance LEDs can achieve 61.8% when the lattice constant is 270 nm.
