Influence of external fields on nonlinear optical rectification and harmonic generation in GaAs/AlGaAs quantum wells
Micro and Nanostructures, cilt.218, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 218
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.micrna.2026.208833
- Dergi Adı: Micro and Nanostructures
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Anahtar Kelimeler: Electric and magnetic field, Intense laser field, Nonlinear optical rectification, Quantum well, Second and third harmonic generations
- Sivas Cumhuriyet Üniversitesi Adresli: Evet
Özet
This work provides a comprehensive theoretical investigation of the nonlinear optical behavior of a tunable smooth profile quantum well heterostructure, focusing on nonlinear optical rectification (NOR), second harmonic generation (SHG), and third harmonic generation (THG) driven by intersubband transitions between the lowest and first excited states. The influence of externally applied electric and magnetic fields, along with an intense laser field, is examined to understand how these factors alter the system's optical response. The electronic structure, including energy eigenvalues and corresponding wavefunctions, is determined through numerical solutions of the Schrödinger equation within the effective mass framework using a matrix diagonalization approach. The results show that external fields induce noticeable red or blue shifts in the resonant peak positions, while the peak amplitudes vary depending on the strength of the applied fields. Tuning the structural parameters of the quantum well provides an additional and efficient mechanism for controlling both the spectral positions and magnitudes of the nonlinear optical responses by modifying the confinement energies and structural asymmetry of the system. The study demonstrates that both the resonance frequencies and nonlinear optical coefficients can be widely tuned through structural design and external field manipulation. These effects are primarily attributed to variations in confinement energies and the redistribution of carrier wavefunctions. The findings demonstrate that the optical response of the system can be effectively engineered by tailoring structural parameters and external field conditions, offering promising potential for the development of high-performance optoelectronic devices operating in the terahertz region.