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X. J. Zhou 1, 2, M. Ji 1, 2, D. Y. An 1, 2, F. Rudau 4, R. Wieland 4, Q. Zhu 1, H. C. Sun 1, 2, L. Y. Hao 1, 2, D. Koelle 4, R. Kleiner 4, H. B. Wang 1, 2, 3* and P. H. Wu 1
1 Research Institute of Superconductor Electronics, Nanjing University, Nanjing 210093, China
2 National Institute for Materials Science, Tsukuba 3050047, Japan
3 Cooperative Innovation Centre of Terahertz Science, Chengdu 610054, China
4 Physikalisches Institut and Center for Quantum Science in LISA+, Universität Tübingen, Tübingen D-72076, Germany
* Email: hbwang1000@gmail.com
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Abstract: Developing compact, tunable sources for terahertz (THz) generation is a highly active field of research. It was found that intrinsic Josephson junction (IJJ) stacks, naturally formed in single crystals of the cuprate superconductor Bi2Sr2CaCu2O8 (BSCCO), can emit coherent radiation in the THz range. With appropriate design, superconducting THz emitters with strong emission power have been fabricated over the last years. To make these emitters versatile for practical applications, e.g. in radio astronomy or for high-speed tele-communication, it is necessary to modulate and tune the THz emission power. We demonstrate two modulation methods. The first method is to use a three-terminal configuration. At high bias currents a hot spot, having a local temperature higher than the superconducting transition temperature, forms in the stack due to Joule-heating. The appearance and the position of the hot spot can be controlled by varying the ratios of the injected currents from two bottom electrodes. The second modulation method is to shine a focused laser beam onto the sample. Also with this method the emission power can be modulated in the high bias regime by moving the laser beam on the surface of the stack.
Keywords: Intrinsic Josephson junctions, Superconducting terahertz emitter, Manipulation of emission
Received: 2016-5-23
Published: 2016-6-30
Cite this article:
X. J. Zhou, M. Ji, D. Y. An, F. Rudau, R. Wieland, Q. Zhu, H. C. Sun, L. Y. Hao, D. Koelle, R. Kleiner, H. B. Wang and P. H. Wu. Modulating the emission properties of superconducting terahertz emitters[J]. International Journal of Terahertz Science and Technology, 2016, Vol.9, No.2: 60-70. DOI:10.11906/TST.060-070.2016.06.06
URL: http://www.tstnetwork.org/10.11906/TST.060-070.2016.06.06
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