Investigation of the Carrier Concentration and Laser Peak Intensity on the Terahertz Pulse Generated by Photoconductive Antennas Based On LT-GaAs

Subject Areas : Majlesi Journal of Telecommunication Devices

Mohamad Ali Malakoutian ¹ , Morteza Fathipour ²

1 - University of Tehran
2 - University of Tehran

Received: 2012-09-09 Accepted : 2012-09-09 Published : 2012-03-01

Keywords: en,

Abstract :

The possibility of terahertz generation has been investigated from a photoconductive switch based on GaAs, gated by a femtosecond laser. The emission properties of photoconductive antenna (PCA) with low-temperature-grown (LT) GaAs have been studied. In such GaAs materials presence of the charged defects induces a redistribution of the electric field between the antenna electrodes. This effect has a huge influence on the amplitude of the radiated terahertz field. In this work we demonstrate that carrier concentration enhances radiation power. Results obtained as a function of the laser excitation power (with 100 fs rise time and 1KHz repetition rate) and carrier concentration are discussed and a comparison of the performance of these devices with a conventional antenna-type (dipole) emitter is given.

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