高Tc超导薄膜约瑟夫逊结光探测研究

STUDY ON HIGH T_c SUPERCONDUCTING THIN FILM LIGHT DETECTOR WITH JOSEPHSoN JUNCTION

我们研制了具有约瑟夫逊效应的高ToGdBa2Cu3O7-薄膜双晶晶界结，对其交直流约瑟夫逊效应进行了观测，并用其进行光探测，用波长为0．6328μm的He－Ne激光器辐照双晶结结区，系统观测了双晶晶界结的光响应特性，得到的最好结果如下：噪音等效功率NEP=1．9×10－13W，归一化探测率D=53×109cmHzW－1，响应率Rv=4．2×107V／W，响应时间r=4．35×10－7s.

The bicrystal granule boundary junctions that have Josephson effects were fabricated withhigh Tc superconducting GdBa2Cu3O7-8 thin film which was deposed on YSZ substrate. And the anglebetween the two granule boundaries are 24°. The DC and AC Josephson effects of junction have beenmeasured at liquid N2 temperature. The typical Josephson behaviour was shown clearly. The lightresponse characteristics of junction for He-Ne laser with 0. 6328μm wave length were measured at77K. The optimum results are as follows:NEP= 1. 9 ×10-13W, D = 5. 3 ×109cmHz1/2W-l,Rv = 4. 2 ×107V/W, =4. 35 ×10-7s.