Narrowband microwave generation with tuneable frequency is demonstrated by illuminating a photoconductive semiconductor switch (PCSS) with a burst-mode fibre laser. The whole system is composed of a high-power linearly polarized burst-mode pulsed fibre laser and a linear-state PCSS. To obtain a high-performance microwave signal, a desired envelope of burst is necessary and a pulse pre-compensation technique is adopted to avoid envelope distortion induced by the gain-saturation effect. Resulting from the technique, homogenous peak power distribution in each burst is ensured. The maximum energy of the laser burst pulse reaches 200 μJ with a burst duration of 100 ns at the average power of 10 W, corresponding to a peak power of 4 kW. When the PCSS is illuminated by the burst-mode fibre laser, narrowband microwave generation with tuneable frequency (0.80–1.12 GHz) is obtained with a power up to 300 W. To the best of the authors’ knowledge, it is the first demonstration of frequency-tuneable narrowband microwave generation based on a fibre laser. The high-power burst-mode fibre laser reported here has great potential for generating high-power arbitrary microwave signals for a great deal of applicable demands such as smart adaptive radar and intelligent high-power microwave systems.

中文翻译：

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大功率线偏振突发模式全光纤激光器及频率可调微波信号的产生

通过用突发模式光纤激光器照亮光电导半导体开关 (PCSS) 来演示具有可调谐频率的窄带微波产生。整个系统由高功率线偏振突发模式脉冲光纤激光器和线态PCSS组成。为了获得高性能的微波信号，需要期望的突发包络，并采用脉冲预补偿技术来避免增益饱和效应引起的包络失真。由于该技术，确保了每个突发中的均匀峰值功率分布。激光突发脉冲的最大能量达到 200 μJ，突发持续时间为 100 ns，平均功率为 10 W，对应的峰值功率为 4 kW。当 PCSS 被突发模式光纤激光器照射时，可产生频率可调的窄带微波（0. 80-1.12 GHz）是在高达 300 W 的功率下获得的。据作者所知，这是基于光纤激光器的频率可调窄带微波生成的首次演示。本文报道的高功率突发模式光纤激光器具有产生高功率任意微波信号的巨大潜力，可满足智能自适应雷达和智能高功率微波系统等大量应用需求。