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Harold

A hetero-structure laser diode model

Electro-Absorption Modulators (QCSE)

Simulation of AlGaAs and SiGe electro-absorption modulators with Harold EAM software

We used Harold EAM to model a AlGaAs electro-absorption modulator and a SiGe electro-absorption modulator relying on the Quantum-Confined Stark Effect (QCSE).

The results are shown below alongside published experimental data; as you can see the simulations are in good agreement with the experiments, with all main features reproduced. We expect that the differences in absolute absorption coefficients are due to scaling ambiguities in the experimental papers.

Comparison with experiment for AlGaAs modulator
AlGaAs modulator: absorption spectra for various values of the bias voltage
(left) Experimental data from [1] and (right) Harold EAM results for (top) TE polarisation and (bottom) TM polarisation

Comparison with experiment for SiGe modulator

SiGe modulator: absorption spectra for various values of the bias voltage
(left) Experimental data from [2] and (right) Harold EAM results for TE polarisation

References

[1] S.-L. Chuang, S. Schmitt-Rink, D. A. B. Miller and D. S. Chemla, “Exciton Green’s function approach to optical absorption in a quantum well with an applied electric field”, Phys. Rev. B, 43, 2, pp. 1500-1509 (1991)

[2] Y.-H. Kuo, Y. K. Lee, Y. Ge, S. Ren, J. E. Roth, T. I. Kamins, D. A. B. Miller, and J. S. Harris, “Quantum-confined stark effect in Ge–SiGe quantum wells on Si for optical modulators”, IEEE J. Sel. Topics Quantum Electron., 12, pp. 1503–1513 (2006)