Enhancement of the refractive index modulation in a modulator based on GaAs/AlGaAs quantum wells

• Published in: Semiconductor science and technology Vol. 34; no. 9; pp. 95005 - 95012
• Main Authors: Zolotarev, V V, Shashkin, I S, Golovin, V S, Soboleva, O S, Shamakhov, V V, Slipchenko, S O, Pikhtin, N A
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.09.2019
• Subjects: coupled quantum well; electro-absorption effect; optical modulator; quantum-confined Stark effect; refractive index change
• ISSN: 0268-1242; 1361-6641
• DOI: 10.1088/1361-6641/ab3131

Approaches of optimization of coupled quantum wells with pronounced quantum-confined Stark effect in order to reach a high refractive index change are described. A numerical simulation was used to determine the optimal design parameters (quantum well width, barrier thickness and composition) based on GaAs/AlGaAs materials with two symmetric quantum wells, which provides the maximum modulation of the refractive index at a small absorption coefficient. It is demonstrated that, with the electric field strength varied within the range 0-20 kV cm−1 at an optical loss for interband absorption not exceeding 10 cm−1, the refractive index can be changed by up to 0.0362.