Abstract Thulium oxide (Tm2O3) film is demonstrated to work as a passive saturable absorber (SA) for stable pulse generation at 1.55-µm region. The Tm2O3 film was fabricated from a commercially available Tm2O3 embedded into polyvinyl alcohol (PVA) as a film host. The obtained Tm2O3 film has an absorption at 1.55-µm region, which corresponds to energy level diagram of thulium. The Tm2O3 film is switched into the all-fibre ring cavity configuration. Self-started Q-switching operation obtained from 84.13 mW until 159.03 mW pump power. The repetition rate increases from 43.82 kHz and stop at 62.70 kHz, while the pulse duration narrowed from 14.00 µs to 9.50 µs. The stability of the pulse train can be confirmed through signal-to-noise ratio (SNR) of fundamental frequency. The maximum output power and pulse energy is 3.90 mW and 6.22 nJ, respectively. As a result, these findings confirm Tm2O3 can be utilised as a potential passive SA to generate laser pulsing at 1.55-µm region.

中文翻译：

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氧化铥薄膜作为脉冲光纤激光器产生的被动可饱和吸收体

摘要 氧化铥 (Tm2O3) 薄膜被证明可用作被动可饱和吸收器 (SA)，可在 1.55 µm 区域产生稳定的脉冲。Tm2O3 薄膜由市售的 Tm2O3 制成，嵌入聚乙烯醇 (PVA) 作为薄膜主体。获得的 Tm2O3 薄膜在 1.55 µm 区域有吸收，这对应于铥的能级图。Tm2O3 薄膜切换到全纤维环形腔结构。从 84.13 mW 到 159.03 mW 泵浦功率获得的自启动 Q 开关操作。重复率从 43.82 kHz 增加并在 62.70 kHz 停止，而脉冲持续时间从 14.00 µs 缩小到 9.50 µs。脉冲串的稳定性可以通过基频的信噪比（SNR）来确定。最大输出功率和脉冲能量分别为 3.90 mW 和 6.22 nJ。