Chowdhury, S

Davies, AG

Dean, P

Hatem, O

Li, L

Linfield, EH

White Rose Research Online

This is a repository copy of Terahertz emission and detection using Fe-doped InGaAs and low-temperature-grown-GaAs photoconductive switches.White Rose Research Online URL for this paper:http://eprints.whiterose.ac.uk/88250/Version: Accepted VersionProceedings Paper:Chowdhury, S, Hatem, O, Dean, P et al. (3 more authors) (2013) Terahertz emission and detection using Fe-doped InGaAs and low-temperature-grown-GaAs photoconductive switches. In: Proceedings. UK Semiconductors 2013, 03-04 Jul 2013, Sheffield, UK. . eprints@whiterose.ac.ukhttps://eprints.whiterose.ac.uk/Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. Terahertz emission and detection using Fe-doped InGaAs and low-temperature-grown-GaAs photoconductive switches  Siddhant Chowdhury,* Osama Hatem, Paul Dean, Lianhe Li, Edmund H. Linfield and A. Giles Davies  School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT, U.K.  *el08s2c@leeds.ac.uk 1. Introduction and Background Photoconductive (PC) switches are one of the most commonly used room temperature sources of broadband terahertz frequency radiation, with low-temperature-grown (LT) GaAs being extensively used for operation at ~800nm excitation wavelengths. However, with advances in materials technology, Fe-doped InGaAs PC switches have recently been used to generate frequencies over a >2 THz bandwidth using both ~800 nm and ~1550 nm excitation wavelengths.1, 2 We report the design and fabrication of PC switches for coherent generation and detection of terahertz-frequency radiation in LT-GaAs, and Fe-doped InGaAs materials with different iron doping levels. PC switches incorporating broadband antennas have been fabricated and characterised using pulsed excitation at wavelengths from 800 nm to 1550 µm. PC switches incorporating log-spiral antennas with interdigitated electrodes have also been characterised for THz emission using both pulsed and continuous-wave excitation. 2. Results Fe-doped InGaAs wafers with a range of doping concentrations were grown using metal organicchemical vapour deposition (MOCVD). Bow-tie antennas were fabricated and successfully te ted for THz emission and detection at wavelengths from 800 nm to 1550 nm (Fig. 1).  We have also demonstrated pulsed terahertz frequency generation using both LT-GaAs and Fe:InGaAs devices incorporating log-spiral antennas and a range of interdigitated electrode designs. We acknowledge the EPSRC (UK), including the COTS programme, as well as the ERC programme ‘TOSCA’, the Royal Society and Wolfson Foundation. 1. C. D. Wood et al., Appl. Phys. Lett. 96, 194104 (2010).  2. O. Hatem, et al., Appl. Phys. Lett. 98, 121107 (2011). Fig. 1 Frequency spectrum and (inset) time-domain signal of the radiation detected from Fe-doped InGaAs PC switches at 1550 nm (50 mW) excitation wavelength. 

Terahertz emission and detection using Fe-doped InGaAs and low-temperature-grown-GaAs photoconductive switches

https://eprints.whiterose.ac.uk/88250/1/Siddhant%20Chowdhury-abstract.pdf

Terahertz emission and detection using Fe-doped InGaAs and low-temperature-grown-GaAs photoconductive switches

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