Quadrupole radiation from terahertz dipole antennas
- 15 October 2000
- journal article
- Published by Optica Publishing Group in Optics Letters
- Vol. 25 (20) , 1556-1558
- https://doi.org/10.1364/ol.25.001556
Abstract
We report what is to our knowledge the first detailed investigation of the polarization state of radiation from lens-coupled terahertz dipole antennas. The radiation exhibits a weak but measurable component that is polarized orthogonally to the orientation of the emitter dipole. The angular radiation pattern of this cross-polarized emission reveals that it is quadrupolar, rather than dipolar, in nature. One can understand this result by taking into account the photocurrent flowing in the strip lines that feed the dipole antenna. A Fresnel–Kirchhoff scalar diffraction calculation is used for calculating the frequency-dependent angular distribution of the radiation pattern, providing satisfactory agreement with the measurements.Keywords
This publication has 12 references indexed in Scilit:
- Evidence of frequency-dependent THz beam polarization in time-domain spectroscopyPublished by SPIE-Intl Soc Optical Eng ,1999
- Design and performance of singular electric field terahertz photoconducting antennasApplied Physics Letters, 1997
- Ionization of Na Rydberg Atoms by Subpicosecond Quarter-Cycle Circularly Polarized PulsesPhysical Review Letters, 1997
- Noncontact semiconductor wafer characterization with the terahertz Hall effectApplied Physics Letters, 1997
- Generation and detection of terahertz pulses from biased semiconductor antennasJournal of the Optical Society of America B, 1996
- T-ray imagingIEEE Journal of Selected Topics in Quantum Electronics, 1996
- Time domain terahertz impulse ranging studiesApplied Physics Letters, 1995
- Radiation patterns from lens-coupled terahertz antennasOptics Letters, 1995
- Characterization of an optoelectronic terahertz beam systemIEEE Transactions on Microwave Theory and Techniques, 1990
- Terahertz beamsApplied Physics Letters, 1989