This work presents a numerical investigation of second-harmonic generation (SHG) by ultrashort femtosecond laser pulses in nonlinear photonic crystals of gallium nitride (GaN) with periodically modulated second-order nonlinear susceptibilityχ2. A coupled-wave model is employed to describe the spatial-temporal evolution of the fundamental and second-harmonic pulses, taking into account linear absorption, group-velocity mismatch, dispersive effects, andquasi-phase matching. The influence of these factors on the conversion efficiency and temporal pulse profiles is systematically analyzed. The results demonstrate that linear absorption inGaN significantly limits the effective interaction length and reduces the achievable conversionefficiency in the femtosecond regime. Dispersive effects lead to a pronounced decrease in conversion efficiency for shorter pulses and cause substantial temporal pulse distortion, includingpulse splitting. In addition, it is shown that the second-harmonic generation process is highly sensitive to deviations of the domain length from the value required for quasi-phase matching,with even moderate fabrication errors resulting in a noticeable reduction in efficiency. Thesefindings highlight the critical role of dispersion management, absorption minimization, andprecise domain engineering in the development of efficient femtosecond frequency convertersbased on GaN.
| Mualliflar | Собиров, О.И., Сапаев, У.К. |
|---|---|
| Jurnal | O‘zbekiston fizika jurnali |
| Nashr sanasi | 2026-05-08 |
| Jild | 28 |
| Son | 1 |
| Til | Rus |
| DOI | 10.52304/.v28i1.634 |
DOI: 10.52304/.v28i1.634 · Maqolaning asl sahifasi
генерация второй гармоники, нелинейная оптика, GaN, фазовый синхронизм, квазисинхронизм фаз, фемтосекундные лазерные импульсы, дисперсия групповой скорости, оптическое преобразование частоты, фотоника, second-harmonic generation, nonlinear optics, GaN, phase matching, quasi-phase matching, femtosecond laser pulses, group-velocity dispersion, optical frequency conversion, photonics
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