The origin of distorted intensity pattern sensed by a lens and antenna coupled AlGaN/GaN-HEMT terahertz detector<xref rid="cpb_28_11_118502fn1" ref-type="fn">*</xref><fn id="cpb_28_11_118502fn1"><label>*</label><p>Project supported by the National Key Research and Development Program of China (Grant No. 2016YFF0100501), the National Natural Science Foundation of China (Grant Nos. 61771466, 61775231, and 61611530708), the Six Talent Peaks Project of Jiangsu Province, China (Grant No. XXRJ-079), the Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant No. 2017372), the Russian Foundation for Basic Research (Grant No. 17-52-53063), and the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20160400).</p></fn>

The origin of distorted intensity pattern sensed by a lens and antenna coupled AlGaN/GaN-HEMT terahertz detector**

Project supported by the National Key Research and Development Program of China (Grant No. 2016YFF0100501), the National Natural Science Foundation of China (Grant Nos. 61771466, 61775231, and 61611530708), the Six Talent Peaks Project of Jiangsu Province, China (Grant No. XXRJ-079), the Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant No. 2017372), the Russian Foundation for Basic Research (Grant No. 17-52-53063), and the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20160400).

Li Xiang^{1, 2}, Sun Jian-Dong^{1, †}, Huang Hong-Juan³, Zhang Zhi-Peng¹, Jin Lin¹, Sun Yun-Fei⁴, Popov V V⁵, Qin Hua^{1, ‡}

(a) Measured photocurrent pattern of a prefocused beam by raster scanning the detector with a silicon lens. (b) Schematic setup for extracting the local self-mixing current. The solid/dashed circuitry is for probing photcurrent in M@D/M@S, respectively. Local photocurrent probed at (c) p1, (d) p2, and (e) p3.