Lithographic antennas at visible frequencies

The response of antenna-coupled thin-film Ni-NiO-Ni diodes to 633-nm helium-neon laser radiation is investigated. Although these detectors and their integrated dipole antennas are optimized for the detection of mid-infrared radiation, a polarization dependence of the measured response to visible radiation is observed. The strongest signals are measured for the polarization parallel to the dipole antenna axis, which demonstrates antenna operation of the device in the visible in addition to the expected thermal and photoelectric effects. The connection structure of the diode also resonates and contributes to the polarization-dependent signal. The receiving area of the dipole antenna is approximately 2 mu m(2). (C) 1999 Optical Society of America.