Laser-driven semiconductor switch for generating nanosecond pulses from a megawatt gyrotron
Laser-driven semiconductor switch for generating nanosecond pulses from a megawatt gyrotron
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DOI：
10.1063/1.5093639
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发表时间：
2019-04-22
影响因子：
4
通讯作者：
Temkin, Richard J.
中科院分区：
文献类型：
--
作者：
Picard, Julian F.;Schaub, Samuel C.;Temkin, Richard J.
采用硅 (Si) 和砷化镓 (GaAs) 晶圆的激光驱动半导体开关 (LDSS) 已用于从 3 μs、110 GHz 陀螺仪产生兆瓦功率级的纳秒级脉冲。使用 532 nm 激光在晶片中诱导光电导，产生 6 ns、230 mJ 脉冲。激光照射单个硅片产生 110 GHz RF 脉冲，宽度为 9 ns，反射率 >70%。在相同条件下，单个 GaAs 晶圆产生 24 ns 110 GHz RF 脉冲，反射率 >78%。对于这两种半导体材料，随着 110 GHz 光束强度的增加，观察到更高的反射率值。使用两个有源晶圆，产生了持续时间低至 3 ns 的可变长度脉冲。该开关在高达 600 kW 的入射 110 GHz 射频功率水平下进行了测试。提出的一维模型与用单个硅晶片获得的实验观察到的时间脉冲形状非常吻合。 LDSS 在高功率毫米波研究中具有许多潜在用途，包括高梯度加速器结构的测试。由 AIP Publishing 许可发布。
A laser-driven semiconductor switch (LDSS) employing silicon (Si) and gallium arsenide (GaAs) wafers has been used to produce nanosecond-scale pulses from a 3 mu s, 110 GHz gyrotron at the megawatt power level. Photoconductivity was induced in the wafers using a 532nm laser, which produced 6 ns, 230 mJ pulses. Irradiation of a single Si wafer by the laser produced 110 GHz RF pulses with a 9 ns width and >70% reflectance. Under the same conditions, a single GaAs wafer yielded 24 ns 110 GHz RF pulses with >78% reflectance. For both semiconductor materials, a higher value of reflectance was observed with increasing 110 GHz beam intensity. Using two active wafers, pulses of variable length down to 3 ns duration were created. The switch was tested at incident 110 GHz RF power levels up to 600 kW. A 1-D model is presented that agrees well with the experimentally observed temporal pulse shapes obtained with a single Si wafer. The LDSS has many potential uses in high power millimeter-wave research, including testing of high-gradient accelerator structures. Published under license by AIP Publishing.