Title :
Micro lens coupled large area photoconductive switch for powerful THz emission
Author :
Matthäus, G. ; Hohmuth, R. ; Voitsch, M. ; Richter, W. ; Riehemann, S. ; Notni, G. ; Nolte, S. ; Tünnermann, A.
Author_Institution :
Inst. of Appl. Phys., Friedrich-Schiller-Univ., Jena
Abstract :
Powerful THz emission based on a finger electrode photoconductive switch attached to a micro lens array is presented. A hexagonal packed lens array directs the incident pump light into specified electrode gaps, yielding only constructive interference in the THz far-field. Using a Ti:Sapphire system operating at 80 MHz with 150 fs pulses and 3 W maximum optical excitation, 0.28 mW THz average power is obtained. The maximum IR-to-THz conversion efficiency is ap1.3times10-4.
Keywords :
electrodes; high-speed optical techniques; light interference; microlenses; optical arrays; optical frequency conversion; photoconducting switches; terahertz wave generation; time resolved spectra; Al2O3:Ti; constructive interference; conversion efficiency; electrode gaps; finger electrode photoconductive switch; frequency 80 MHz; hexagonal packed lens array; large area emitter; microlens array; optical excitation; power 0.28 mW; power 3 W; terahertz emission; time 150 fs; Biomedical optical imaging; Electrodes; Fingers; Gallium arsenide; Lenses; Optical pumping; Optical sensors; Photoconductivity; Surface emitting lasers; Switches;
Conference_Titel :
Infrared, Millimeter and Terahertz Waves, 2008. IRMMW-THz 2008. 33rd International Conference on
Conference_Location :
Pasadena, CA
Print_ISBN :
978-1-4244-2119-0
Electronic_ISBN :
978-1-4244-2120-6
DOI :
10.1109/ICIMW.2008.4665625
