| Autor: |
Thitikorn Kemsri, Guiru Gu, Cheryl Schnitzer, Michaela Sullivan, Boyang Xiang, Ainaz GhafaryAghdam, Lin Li, Xuejun Lu |
| Předmět: |
|
| Zdroj: |
Journal of Physics D: Applied Physics; 9/18/2019, Vol. 52 Issue 38, p1-1, 1p |
| Abstrakt: |
In this paper, we report the study of the frequency-dependent plasmonic enhancement of a circular disk nano-optical antenna array and the photo-response of the optical antenna enhanced photodetector at different frequencies using a femtosecond (fs) laser frequency comb. A fs-laser frequency comb can provide hundreds of evenly spaced harmonic frequencies and thus allows simultaneous measurement of the plasmonic optical antenna enhancement effect at these harmonic frequencies. This offers a highly efficient frequency-dependent measurement approach compared to the conventional method of modulating of a c.w. laser, which measures the frequency response at each frequency. The impulse response of the circular disk nano-optical antenna array and the electric-field (E-field) distribution profile are simulated under a fs laser illumination. The light intensity spectrum is simulated and verified to have uniform intensities on the harmonic frequencies within the ±5 GHz frequency range. The photocurrent densities in different regions of a GaAs p-i-n photodetector are analyzed together with their frequency dependence at the harmonic frequencies of the fs laser frequency comb with a repetition rate of MHz. A circular disk nano-optical antenna array enhanced GaAs p-i-n photodetector was fabricated and measured using a fs laser frequency comb with the same repetition rate. The nano-optical antenna can provide ~20 dB enhancement for the harmonic frequencies and extend the detector cut-off frequency from 2.4 GHz to 4.2 GHz. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
