Passively Q-switched fibre laser generation for mid infrared using aluminium-based MAX phase materials

• المؤلف الرئيسي: Mohd Nasir, Amal Muaz
• التنسيق: أطروحة
• اللغة: الإنجليزية; الإنجليزية
• منشور في: 2025
• الموضوعات: T Technology; TA Engineering (General). Civil engineering (General)
• الوصول للمادة أونلاين: http://eprints.utem.edu.my/id/eprint/29350/

Pulsed fibre lasers are increasingly vital in modern photonics due to their compactness, efficiency, and high peak power, supporting applications in sensing, imaging, and materials processing. Among pulse generation techniques, passive Q-switching is preferred for its simplicity and low cost. However, identifying saturable absorbers (SAs) that are stable, efficient, and compatible with mid-infrared operation remains a challenge. This study explores the integration of aluminium-based MAX phase materials; Molybdenum Titanium Aluminium Carbide (Mo2Ti2AlC2) and Titanium Aluminium Nitride (Ti4AlN3), as SAs for passively Q-switched erbium-doped fibre lasers (EDFLs) operating near 1.55 µm. The MAX phase materials were dispersed in polyvinyl alcohol (PVA) to form homogeneous films via drop-casting. Each film was sandwiched between standard fibre ferrules and inserted into a ring-cavity EDFL for passive Q-switching. Optical characterisation of the materials revealed suitable absorption and modulation properties for Q-switch operation. The Mo2Ti2AlC2-PVA film exhibited a linear absorption of 1.5 dB and enabled self-started Q-switching with pulse durations from 21.7 µs to 8.9 µs and repetition rates from 20.45 kHz to 40.40 kHz, achieving a maximum output power of 1.1 mW and pulse energy of 27.2 nJ. In comparison, the Ti4AlN3-PVA film showed a modulation depth of 17% and produced pulses at 1559.4 nm with a minimum duration of 5.75 µs at 59.2 kHz, yielding a peak output power of 2.34 mW and pulse energy of 39.5 nJ. These results confirm the effectiveness of aluminium-based MAX phase materials as practical SAs for mid-infrared fibre lasers. Their strong nonlinear absorption, thermal stability, and ease of integration offer a promising solution for the development of compact, stable, and high-performance pulsed laser systems in emerging photonic applications.