Modeling of Ultrafast Waveguided Electro-Absorption Modulator at Telecommunication Wavelength (λ = 1.55 μm) Based on Intersubband Transition in an InGaAs/AlAs/AlAsSb Asymmetric Coupled Double Quantum Well Lattice-Matched to InP

We investigated theoretically a waveguided EAM (Electro-Absorption Modulator) based on ISBT (Intersubband Transitions) in an In
_(0.53)
Ga
_(0.47)
As/AlAs/AlAs
_(0.56)
Sb
_(0.44)
A-CDQWs (Asymmetric Coupled Double Quantum Wells) lattice-matched to InP at telecommunication wavelength (
$\lambda =1.55~\mu \text{m}$
) which offers ultrahigh-speed and moderate voltage swing. Likewise, the temperature dependency in the In
_(0.53)
Ga
_(0.47)
As/AlAs/AlAs
_(0.56)
Sb
_(0.44)
A-CDQWs was investigated at different temperatures from 300 K to 400 K and evidently the InP-based ISB (Intersubband) modulator offers better temperature stability (~ 0.05 nm/C) compared to the InP-based IB (Interband) modulator. The EAM investigated here is anticipated to have a RC-limited speed (
$f_{3d\,B}$
) of ~300 GHz with insertion loss of 5.1 dB, 10 dB extinction ratio and 5.18 dB/V modulation efficiency at a peak-to-peak voltage of 2.0 V which can support a data rate of up to 600 Gbps and beyond.