太赫兹低损耗金刚石-无氧铜输能窗研究OACSTPCD

In order to decrease the transfer loss of RF window and improve the output power of terahertz vacuum electronic devices,dia-mond-oxygen free high conductance copper(OFHC)pill-box RF window in terahertz regime is studied for the first time.A multi-slot structure is proposed to reduce the sealing stress which is caused by the mismatch of the thermal expansion coefficient between diamond and OFHC.The simulation predicts that the multi-slot structure reduces sealing stress from 210 MPa to 50 MPa,which is lower than the average sealing strength of diamond-OFHC tensile piece.After the sealing experiment,the RF window is proved to be airtight with a he-lium leak rate lower than 1×10-11(Pa·m3)/s.The measurement result shows that the diamond-OFHC RF window is 2 dB less transfer loss than diamond-Kovar RF window,which means that the output power is increased by 60%.This research settles an essential techno-logical foundation for developing high power terahertz resource.