2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/141168We have demonstrated efficient intersubband electroabsorption in InGaAs/InAlGaAs/InAlAs step quantum wells grown by metal-organic vapor phase epitaxy (MOVPE). An absorption modulation of 6 dB at $λ=6.0 μ$m due to Stark shift of the IS absorption was achieved at a low voltage swing of $\pm 0.5$ V in a multipass waveguide structure. Based on the experimental results it is estimated that an electroabsorption modulator with a low peak-to-peak voltage of $V_{pp}=0.9$ V can yield a modulation speed of $f_{3dB} \approx 120$ GHz with the present material by using a strongly confining surface plasmon waveguide of 30 $μ$m length.3 pages, 3 figuresOpticstext