We demonstrate an increase of optical transmittance and saturable absorption of laser-treated free-standing single-walled carbon nanotube (SWNT) films. The combined acid and low-power non-destructive laser treatment ensures an enhancement of linear transmittance across the visible range and double-digit increase of the saturable absorption of femtosecond laser radiation at 795 nm. The saturable absorption coefficient and the ratio of saturable to non-saturable losses increase by 26% and 35%, correspondingly, while the saturation intensity decreases by 20% because of the treatment. Our analysis indicates that with the performed treatment one can significantly improve the nonlinear optical properties of free-standing SWNT-based ultrafast saturable absorbers.

中文翻译：

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激光处理的自立式碳纳米管薄膜中增强的饱和吸收

我们证明了激光处理的自立式单壁碳纳米管（SWNT）膜的透光率和饱和吸收率的增加。结合使用酸和低功率无损激光处理，可以确保提高可见光范围内的线性透射率，并提高795 nm飞秒激光辐射的饱和吸收率达到两位数。饱和吸收系数和饱和与非饱和损耗之比分别增加了26％和35％，而饱和强度由于这种处理而降低了20％。我们的分析表明，通过进行这种处理，可以显着改善基于独立式SWNT的超快可饱和吸收体的非线性光学性能。