Terahertz radiation of a butterfly-shaped photoconductive antenna(invited)
| Autor: | Mingguang Tuo, Wei Ren Ng, Michael E. Gehm, Hao Xin, Jitao Zhang, Min Liang |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Photocurrent
Electron mobility Materials science Condensed Matter::Other business.industry Terahertz radiation Photoconductivity Physics::Optics Aerospace Engineering Carrier lifetime Radiation Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Atomic and Molecular Physics and Optics Radiation properties Condensed Matter::Materials Science Space and Planetary Science Optoelectronics Laser power scaling Electrical and Electronic Engineering business |
| Zdroj: | Infrared and Laser Engineering. 48:402001 |
| ISSN: | 1007-2276 |
| DOI: | 10.3788/irla201948.0402001 |
| Popis: | The terahertz(THz) far-field radiation properties of a butterfly-shaped photoconductive antenna (PCA) were experimentally studied using a home-built THz time-domain spectroscopy(THz-TDS) setup. To distinguish the contribution of in-gap photocurrent and antenna structure to far-field radiation, polarization-dependent THz field was measured and quantified as the illuminating laser beam moved along the bias field within the gap region of electrodes. The result suggests that, although the far-field THz radiation originates from the in-gap photocurrent, the antenna structure of butterfly-shaped PCA dominates the overall THz radiation. In addition, to explore the impact of photoconductive material, radiation properties of butterfly-shaped PCAs fabricated on both low-temperature-grown GaAs(LT-GaAs) and semi-insulating GaAs(Si-GaAs) were characterized and compared. Consistent with previous experiments, it is observed that while Si-GaAs-based PCA can emit higher THz field than LT-GaAs-based PCA at low laser power, it would saturate more severely as laser power increased and eventually be surpassed by LT-GaAs-based PCA. Beyond that, it is found the severe saturation effect of Si-GaAs was due to the longer carrier lifetime and higher carrier mobility, which was confirmed by the numerical simulation. |
| Databáze: | OpenAIRE |
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