High-brightness tapered lasers with photonic crystal structures are designed and fabricated.A narrow taper angle is designed for the tapered section.The device delivers an output power of 3.3 W and a maximum wall-plug...High-brightness tapered lasers with photonic crystal structures are designed and fabricated.A narrow taper angle is designed for the tapered section.The device delivers an output power of 3.3 W and a maximum wall-plug efficiency of 43%.The vertical beam divergence is around 110 at different currents.Nearly diffraction-limited beam qualities for the vertical and lateral directions are obtained.The lateral beam quality factor M2 is below 2.5 and the vertical M2 value is around 1.5 across the whole operating current range.The maximum brightness is 85 MW·cm-2sr-1.When the current is above 3.3 A,the brightness is still above 80 MW·cm-2sr-1.展开更多
Pseudospark discharge is a kind of gas discharge Which occurs at high voltages(10kV—【1MV) and low pressures (1—100Pa) in a special axial symmetric geometry—the so-called pseudospark chamber (PSC). The device with ...Pseudospark discharge is a kind of gas discharge Which occurs at high voltages(10kV—【1MV) and low pressures (1—100Pa) in a special axial symmetric geometry—the so-called pseudospark chamber (PSC). The device with an insulator disc being in-serted between a hollow cathode (HC) and a plane anode both with a common centralchannel is called the single-gap PSC. We call stacks of alternative insulator and展开更多
In order to resolve the prevailing problems in conventional light-emitting diodes (LEDs), novel high-efficiency tunneling-regenerated multi-active-region (TRMAR) LEDs are proposed, which have such advantages as low he...In order to resolve the prevailing problems in conventional light-emitting diodes (LEDs), novel high-efficiency tunneling-regenerated multi-active-region (TRMAR) LEDs are proposed, which have such advantages as low heat generation, carrier overflow level and non-radiation re-combination rate and whose quantum efficiency and the output optical power can be scaled with the number of the active regions. Experiments show that the on-axis luminous intensity of TRMAR LEDs increases linearly with the number of active regions. The novel LEDs have high quantum efficiency under low current injection and their maximum on-axis luminous intensity exceeds 5 candelas at 20 mA current injection at the peak wavelength of 625 nm with a 15?angle cap.展开更多
The Hefei Advanced Light Facility(HALF)proposed by the National Synchrotron Radiation Laboratory(NSRL)is a diffraction-limited storage ring(DLSR),which plans to use a full energy linac as the injector.To ensure inject...The Hefei Advanced Light Facility(HALF)proposed by the National Synchrotron Radiation Laboratory(NSRL)is a diffraction-limited storage ring(DLSR),which plans to use a full energy linac as the injector.To ensure injection efficiency,the injection beam needs to have low emittance.Therefore,a photocathode radio frequency(RF)gun was developed in the HALF R&D project.The gun is designed to deliver high-quality electron bunches with a typically 0.5 nC charge and~4.5 MeV energy with low emittance.The initial system commission with an electron beam was completed at the end of 2020,and a stable 1.2–1.4 mm.mrad emittance with a bunch charge of 500 pC was demonstrated.In this paper,we report the experimental results and experience obtained during the commission,including the RF gun,drive laser system,and beam diagnostics.展开更多
基金Supported by the National Key Research and Development Program of China under Grant Nos 2016YFB0402203 and 2016YFA0301102the National Natural Science Foundation of China under Grant Nos 61535013 and 91850206
文摘High-brightness tapered lasers with photonic crystal structures are designed and fabricated.A narrow taper angle is designed for the tapered section.The device delivers an output power of 3.3 W and a maximum wall-plug efficiency of 43%.The vertical beam divergence is around 110 at different currents.Nearly diffraction-limited beam qualities for the vertical and lateral directions are obtained.The lateral beam quality factor M2 is below 2.5 and the vertical M2 value is around 1.5 across the whole operating current range.The maximum brightness is 85 MW·cm-2sr-1.When the current is above 3.3 A,the brightness is still above 80 MW·cm-2sr-1.
基金Project supported by the National Natural Science Foundation of China.
文摘Pseudospark discharge is a kind of gas discharge Which occurs at high voltages(10kV—【1MV) and low pressures (1—100Pa) in a special axial symmetric geometry—the so-called pseudospark chamber (PSC). The device with an insulator disc being in-serted between a hollow cathode (HC) and a plane anode both with a common centralchannel is called the single-gap PSC. We call stacks of alternative insulator and
基金supported by Special Funds for Major State Basic Research Project of China(No.G20000683-02)the National Natural Science Foundation of China(Grant Nos.69889601,60276033,60077004)+2 种基金Chinese 863 Plan(No.2002AA312070)Beijing Natural Science Foundation(No.4002003)Beijing Education Committee Project(No.99270602).
文摘In order to resolve the prevailing problems in conventional light-emitting diodes (LEDs), novel high-efficiency tunneling-regenerated multi-active-region (TRMAR) LEDs are proposed, which have such advantages as low heat generation, carrier overflow level and non-radiation re-combination rate and whose quantum efficiency and the output optical power can be scaled with the number of the active regions. Experiments show that the on-axis luminous intensity of TRMAR LEDs increases linearly with the number of active regions. The novel LEDs have high quantum efficiency under low current injection and their maximum on-axis luminous intensity exceeds 5 candelas at 20 mA current injection at the peak wavelength of 625 nm with a 15?angle cap.
基金supported by Hefei Advanced Light Facility R&D project and the National Natural Science Foundation of China (No.11775216)
文摘The Hefei Advanced Light Facility(HALF)proposed by the National Synchrotron Radiation Laboratory(NSRL)is a diffraction-limited storage ring(DLSR),which plans to use a full energy linac as the injector.To ensure injection efficiency,the injection beam needs to have low emittance.Therefore,a photocathode radio frequency(RF)gun was developed in the HALF R&D project.The gun is designed to deliver high-quality electron bunches with a typically 0.5 nC charge and~4.5 MeV energy with low emittance.The initial system commission with an electron beam was completed at the end of 2020,and a stable 1.2–1.4 mm.mrad emittance with a bunch charge of 500 pC was demonstrated.In this paper,we report the experimental results and experience obtained during the commission,including the RF gun,drive laser system,and beam diagnostics.
