Terahertz photonics

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Photoconductive detection of arbitrary polarised terahertz pulses

(2006)

Authors:

E Castro-Camus, J Lloyd-Hughes, MB Johnston, MD Fraser, HH Tan, C Jagadish
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Terahertz emission and lifetime measurements of ionimplanted semiconductors: Experiment and simulation

Optics InfoBase Conference Papers (2006)

Authors:

J Lloyd-Hughes, E Castro-Camus, MD Fraser, HH Tan, C Jagadish, MB Johnston

Abstract:

The spectral width of terahertz emission from ion-implanted terahertz emitters increases with ion damage, owing to ultrafast carrier capture. Carrier dynamics simulations reinforce these findings. Optical-pump, terahertz-probe experiments confirm the subpicosecond lifetimes of these materials. © 2006 Optical Society of America.

Broadband terahertz emission from ion-implanted semiconductors

SPRINGER PROC PHYS 110 (2006) 77-80

Authors:

J Lloyd-Hughes, E Castro-Camus, MD Fraser, HH Tang, C Ja-gadish, MB Johnston

Abstract:

The terahertz radiation emitted from Fe+ ion-implanted InGaAs surface emitters and InP photoconductive switches was measured. We experimentally observe an increase in the spectral width of terahertz radiation at greater ion damage, which we attribute to the ultrafast capture of photoexcited carriers. Results from a three-dimensional carrier dynamics simulation support this explanation.
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Carrier dynamics in ion-implanted semiconductors studied by simulation and observation of terahertz emission - art. no. 61180K

P SOC PHOTO-OPT INS 6118 (2006) K1180-K1180

Authors:

J Lloyd-Hughes, E Castro-Camus, MD Fraser, HH Tan, C Jagadish, MB Johnston

Abstract:

We have experimentally measured the terahertz radiation from a series of ion-implanted semiconductors, both from the bare semiconductor surface and from photoconductive switches fabricated on them. GaAs was implanted with As+ ions, and InGaAs and InP with Fe+ ions, and all samples were annealed post implantation. An increase in emission power is observed at high frequencies, which we attribute to the ultrafast trapping of carriers. We use a three-dimensional carrier dynamics simulation to model the emission process. The simulation accurately predicts the experimentally observed bandwidth increase, without resorting to any fitting parameters. Additionally, we discuss intervalley scattering, the influence of space-charge fields, and the relative performance of InP, GaAs and InAs based photoconductive emitters.
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Detecting the full polarization state of terahertz transients - art. no. 61200Q

P SOC PHOTO-OPT INS 6120 (2006) Q1200-Q1200

Authors:

E Castro-Camus, J Lloyd-Hughes, MD Fraser, HH Tan, C Jagadish, MB Johnston

Abstract:

We have developed a detector which records the full polarization state of a terahertz (THz) pulse propagating in free space. The three-electrode photoconductive receiver simultaneously records the electric field of an electromagnetic pulse in two orthogonal directions as a function of time. A prototype device fabricated on Fe+ ion implanted InP exhibited a cross polarized extinction ratio better than 390:1. The design and optimization of this device are discussed along with its significance for the development of new forms of polarization sensitive time domain spectroscopy, including THz circular dichroism spectroscopy.
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