Lithuanian Journal of Physics article / Lietuvos fizikos žurnalo straipsnis

DEPENDENCE OF TERAHERTZ PHOTOCONDUCTIVE SWITCH PERFORMANCE ON METAL CONTACT GEOMETRY
Ignas Nevinskas^a, Mindaugas Kamarauskas^a, Andrejus Geižutis^a, Vitalij Kovalevskij^a, Andrius Bičiūnas^a, Andrzej Urbanowicz^a, Ričardas Norkus^a, and Kęstutis Ikamas^a,b,c
^aCenter for Physical Sciences and Technology, Saulėtekio 3, 10257 Vilnius, Lithuania
^bInstitute of Applied Electrodynamics and Telecommunications, Vilnius University, Saulėtekio 3, 10257 Vilnius, Lithuania
^cThe General Jonas Žemaitis Military Academy of Lithuania, Šilo 5A, 10322 Vilnius, Lithuania
Email: ignas.nevinskas@ftmc.lt
Received 18 June 2024; revised 15 October 2024; accepted 15 October 2024

This study investigates the emission and spectral characteristics of photoconductive THz switches employing coplanar stripline contact geometries fabricated on a GaAs substrate. The experimental results reveal how the power outputs as well as the spectral shape are significantly influenced by the strip width dimension. Utilizing the Drude–Lorentz conductivity model, photocarrier dynamics were analyzed through an RLC circuit framework, offering insights into how the contact design influences the spectral response. Our findings suggest that matching the photocurrent impedance to that of the metallic contacts is critical to improving the eﬀiciency of these devices.
Keywords: photoconductive switch, terahertz, THz, GaAs, gallium arsenide

TERAHERCINIŲ FOTOJUNGIKLIŲ CHARAKTERISTIKŲ PRIKLAUSOMYBĖS NUO METALINIŲ KONTAKTŲ GEOMETRIJOS
Ignas Nevinskas^a, Mindaugas Kamarauskas^a, Andrejus Geižutis^a, Vitalij Kovalevskij^a, Andrius Bičiūnas^a, Andrzej Urbanowicz^a, Ričardas Norkus^a, Kęstutis Ikamas^a,b,c

^aFizinių ir technologijos mokslų centras, Vilnius, Lietuva
^bVilniaus universiteto Taikomosios elektrodinamikos ir telekomunikacijų institutas, Vilnius, Lietuva
^cGenerolo Jono Žemaičio Lietuvos karo akademija, Vilnius, Lietuva

Tiriamos terahercinių fotojungiklių ant GaAs padėklo emisijos ir spektro charakteristikų priklausomybės nuo koplanarinių juostelių kontaktų geometrijos. Eksperimentiškai parodoma, kaip stipriai keičiasi išspinduliuojama galia bei spektro forma nuo kontaktinės juostelės pločio. Naudojantis Drude ir Lorentz elektrinio laidumo modeliu, fotokrūvininkų dinamika išanalizuota RLC grandinės modelyje, suteikiančiame įžvalgų apie kontaktų dizaino įtaką fotojungiklių atsakui. Nustatėme, kad suderinti fotosrovės impedansą su metalinių kontaktų impedansu yra kertinis reikalavimas šių prietaisų našumui padidinti.

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