Time behavior of field screening effects in small-size GaAs photoconductive terahertz antenna
Tianyi WANG, Zhengang YANG, Si ZOU, Kejia WANG, Shenglie WANG, Jinsong LIU
Time behavior of field screening effects in small-size GaAs photoconductive terahertz antenna
The field screening effects in small-size GaAs photoconductive (PC) antenna are investigated via the well-known pump and probe terahertz (THz) generation technique. The peak amplitude of the THz pulses excited by the probe laser pulse as a function of the pump-probe time delay was measured. An equivalent-circuit model was used to simulate the experimental data. Based on the good agreement between the results of simulation and experiment, the time behavior of the radiation and space-charge fields was simulated. The results show that the space-charge screening dominantly determines the device response in the whole time, while the radiation filed screening plays a key role in initial time which strongly affects the peak THz field. The parameter analysis was performed, which may be valuable on the optimum design for the antenna as a THz emitter.
GaAs photoconductive (PC) antenna / field screening effects / terahertz (THz) emitter
[1] |
Auston D H, Cheung K P, Smith P R. Picosecond photoconducting Hertzian dipoles. Applied Physics Letters, 1984, 45(3): 284–286
CrossRef
Google scholar
|
[2] |
Katzenellenbogen N, Grischkowsky D. Efficient generation of 380 fs pulses of THz radiation by ultrafast laser pulse excitation of a biased metal-semiconductor interface. Applied Physics Letters, 1991, 58(3): 222–224
CrossRef
Google scholar
|
[3] |
Tonouchi M, Kawasaki N, Yoshimura T, Wald H, Seidel P. Pump and probe terahertz generation study of ultrafast carrier dynamics in low-temperature grown-GaAs. Japanese Journal of Applied Physics, 2002, 41(Part 2, No. 6B): L706–L709
CrossRef
Google scholar
|
[4] |
Siebert K J, Lisauskas A, Löffler T, Roskos H. Field screening in low-temperature-grown GaAs photoconductive antennas. Japanese Journal of Applied Physics, 2004, 43(3): 1038–1043
CrossRef
Google scholar
|
[5] |
Yano R, Gotoh H, Hirayama Y, Miyashita S. Systematic pump-probe terahertz wave emission spectroscopy of a photoconductive antenna fabricated on low-temperature grown GaAs. Journal of Applied Physics, 2004, 96(7): 3635–3638
CrossRef
Google scholar
|
[6] |
Loata G C, Thomson M D, Löffler T, Poskos H C. Radiation field screening in photoconductive antennae studied via pulsed terahertz emission spectroscopy. Applied Physics Letters, 2007, 91(23): 232506-1–232506-3
|
[7] |
Pedersen J E, Lyssenko V G, Hvam J M, Jepsen P U, Keiding S R, So̸rensen C B, ̸Lindelof P E. Ultrafast local field dynamics in photoconductive THz antennas. Applied Physics Letters, 1993, 62(11): 1265–1267
CrossRef
Google scholar
|
[8] |
Jacobsen R H, Birkelund K, Holst T, Jepsen P U, Keiding S R. Interpretation of photocurrent correlation measurements used for ultrafast photoconductive switch characterization. Journal of Applied Physics, 1996, 79(5): 2649–2657
CrossRef
Google scholar
|
[9] |
Jepsen P U, Jacobsen R H, Keiding S R. Generation and detection of terahertz pulses from biased semiconductor antennas. Journal of the Optical Society of America B, Optical Physics, 1996, 13(11): 2424–2436
CrossRef
Google scholar
|
[10] |
Loata G C. Investigation of low-temperature-grown GaAs photoconductive antennae for continuous-wave and pulsed terahertz generation. Dissertation for the Doctoral Degree. Frankfurt: Universitätsbibliothek Frankfurt am Main, 2007
|
/
〈 | 〉 |