Title :
High power terahertz radiation with diamond photoconductive antenna array
Author :
Yoneda, H. ; Tokuyama, K. ; Ueda, K. ; Yamamoto, H. ; Baba, K.
Author_Institution :
Device Mater. Res. Lab., NEC Corp., Japan
Abstract :
High power terahertz (THz) radiation was generated from a photoconductive diamond switch array for the first time. This device consisted of more than 2000 photoconductive gaps and a binary mask for spatial modulation of pumping laser. Due to-the high breakdown threshold of diamond and the over-coated gap structure for preventing surface flashover, high electric field strength (2/spl times/10/sup 6/ V/cm) can be applied on each gap with DC mode. A 10 nJ, 1.5 ps FWHM free propagating electromagnetic pulse was observed from 10 mm/sup 2/ effective emission area at E=10/sup 5/ V/cm. This radiation was focused on to 1.4 mm/spl phi/ spot with F/2 optics. As there was no severe saturation observed in photoconductive phenomena in CVD diamond up to 10/sup 6/ V/cm, the focusing intensity can be increased to GW/cm/sup 2/ level by increasing the applied electric field and the switching area.
Keywords :
diamond; electric strength; elemental semiconductors; flashover; masks; photoconducting devices; submillimetre wave antennas; submillimetre wave generation; 1.5 ps; 10 nJ; C; DC mode; FWHM free propagating electromagnetic pulse; binary mask; breakdown threshold; effective emission area; electric field strength; focusing intensity; high power terahertz radiation; over-coated gap structure; photoconductive antenna array; photoconductive gaps; spatial modulation; surface flashover; switching area; Electric breakdown; Electromagnetic propagation; Flashover; Laser excitation; Laser modes; Photoconducting devices; Photoconductivity; Power generation; Pump lasers; Switches;
Conference_Titel :
Infrared and Millimeter Waves, 2000. Conference Digest. 2000 25th International Conference on
Conference_Location :
Beijing, China
Print_ISBN :
0-7803-6513-5
DOI :
10.1109/ICIMW.2000.892937
