Opt Express. 2023 Feb 13;31(4):6704-6712. doi: 10.1364/OE.483978.
In this contribution, we measured the third-order nonlinear optical response of bismuth oxychloride (BiOCl) nanosheets with the open-aperture (OA) and the closed-aperture (CA) Z-scan techniques with a variable excitation intensity at 1.34 µm. The effective nonlinear absorption coefficient βeff and the nonlinear refractive index n of the prepared BiOCl nanosheets with abundant oxygen vacancies were obtained under the excitation intensity. The third-order nonlinear optical susceptibility |χ| was 1.64 × 10 esu. The nonlinear optical features of BiOCl enabled it as a superb saturable absorber for pulse laser generation. As a consequence, we demonstrated the first passively Q-switched Nd:GdVO laser with the BiOCl saturable absorber, producing a shortest pulse duration of 543 ns and a highest repetition rate of 227 kHz, leading to a maximum pulse energy of 74 nJ. Our findings show that BiOCl nanosheets with oxygen vacancies have large nonlinear optical sensitivities and can be exploited to generate optical pulses.
在本研究中，我们使用开孔径（OA）和闭孔径（CA）Z 扫描技术，在 1.34μm 处用可变激发强度测量了氧空位丰富的 BiOCl 纳米片的三阶非线性光学响应。在激发强度下，获得了具有丰富氧空位的 BiOCl 纳米片的有效非线性吸收系数βeff和非线性折射率 n。三阶非线性光学磁化率 |χ| 为 1.64×10 esu。BiOCl 的非线性光学特性使其成为用于脉冲激光产生的出色可饱和吸收体。因此，我们展示了第一个使用 BiOCl 可饱和吸收体的被动调 Q Nd：GdVO 激光器，产生最短的脉冲持续时间为 543ns 和最高的重复率为 227kHz，从而产生最大的脉冲能量为 74nJ。我们的研究结果表明，具有氧空位的 BiOCl 纳米片具有较大的非线性光学灵敏度，可用于产生光脉冲。
