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arXiv · 2509.13639

10-W Sub-100-fs Ultrafast Cr:ZnS/ZnSe MOPA System enabled by doping gradient engineering

Guangzi Feng·Xiyue Zhang·Yuchen Wang·Weibo Wu·Gianluca Galzerano·Qing Wang·Ting Yu·Yujie Peng·Jintai Fan·Benxue Jiang·Yuxin Leng·Long Zhang
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Abstract

We report on a high-power mid-infrared femtosecond master oscillator power amplifier (MOPA) system, employing Cr:ZnS and Cr:ZnSe polycrystals with fine-tuned doping profiles. Based on the soft-aperture Kerr-lens mode-locking in the soliton regime, the seed oscillator generates ~40-fs pulses with a repetition rate ~173 MHz with an average power close to 400 mW. The amplification process of the seed pulse train is investigated in depth in a single-pass configuration for both Cr:ZnS and Cr:ZnSe crystal rods. For further power scaling, a dual-stage MOPA system has been implemented, generating pulse trains with an average power up to 10.4 W, limited only by the pump source, with a re-compressed pulse duration of 78 fs using a dispersion compensator comprising chirped mirrors and sapphire plates. This work paves the way for further power scaling of mid-infrared Cr:ZnS/ZnSe ultrafast laser systems without moving parts for applications in material processing, remote sensing and medicine.

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Guangzi Feng, Xiyue Zhang, Yuchen Wang, Weibo Wu, Gianluca Galzerano, Qing Wang, Ting Yu, Yujie Peng, Jintai Fan, Benxue Jiang, Yuxin Leng, Long Zhang. 2025-09-17. 10-W Sub-100-fs Ultrafast Cr:ZnS/ZnSe MOPA System enabled by doping gradient engineering. https://arxiv.org/abs/2509.13639

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