Patent ID: 8878134

Claim:
A photoconductive antenna adapted to generate terahertz waves when irradiated by pulsed light, the photoconductive antenna comprising: a first conductive region made of a semiconductor material containing a first conductive type impurity; a second conductive region made of a semiconductor material containing a second conductive type impurity different from the first conductive type impurity, the second conductive region being spaced apart from the first conductive region to form a gap therebetween in a top plan view of the photoconductive antenna; and a semiconductor region positioned in the gap between the first conductive region and the second conductive region in the top plan view, and made of a semiconductor material having a carrier density that is lower than a carrier density of the semiconductor material of the first conductive layer or a carrier density of the semiconductor material of the second conductive layer, an interfacial surface of the semiconductor region positioned in the gap being flush with a first interfacial surface of the first conductive region and a first interfacial surface of the second conductive region, and a second interfacial surface of the first conductive region positioned on an opposite side from the first interfacial surface and a second interfacial surface of the second conductive region positioned on an opposite side from the first interfacial surface being positioned on the same side with respect to the interfacial surface of the semiconductor region positioned in the gap.