Gallium arsenide (GaAs) semiconductor wires have emerged as potent candidates for nonlinear optical devices, necessitating bandgap engineering for an expanded operational wavelength range. We report the successful growth of strain-mediated GaAs microwires (MWs) with an average diameter of 1.1 μm. The axial tensile strain in these wires, as measured by X-ray diffraction and Raman scattering, ranges from 1.61 % to 1.95 % and from 1.44 % to 2.03 %, respectively. This strain condition significantly reduces the bandgap of GaAs MWs compared to bulk GaAs, enabling a response wavelength extension up to 1.1 μm. Open aperture Z-scan measurements reveal a nonlinear absorption coefficient of −15.9 cm/MW and a third-order magnetic susceptibility of −2.8 × 10−8 esu at 800 nm for these MWs. I-scan measurements further show that the GaAs saturable absorber has a modulation depth of 7.9 % and a nonsaturation loss of 3.3 % at 1050 nm. In laser applications, GaAs MWs have been effectively used as saturable absorbers for achieving Q-switched and dual-wavelength synchronous mode-locking operations in Yb-bulk lasers. These results not only offer new insights into the use of large diameter semiconductor wires but also expand the potential for applications requiring bandgap tuning.

中文翻译：

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应变介导砷化镓微丝在近红外区域的非线性光学响应

砷化镓 (GaAs) 半导体线已成为非线性光学器件的有力候选者，因此需要带隙工程来扩大工作波长范围。我们报告了平均直径为 1.1 μm 的应变介导 GaAs 微线 (MW) 的成功生长。通过 X 射线衍射和拉曼散射测量，这些线材的轴向拉伸应变范围分别为 1.61% 至 1.95% 和 1.44% 至 2.03%。与块状 GaAs 相比，这种应变条件显着降低了 GaAs MW 的带隙，从而使响应波长扩展至 1.1 μm。开孔 Z 扫描测量显示非线性吸收系数为 -15.9 cm/MW，三阶磁化率为 -2.8 × 10−8这些 MW 的 esu 波长为 800 nm。I 扫描测量进一步表明，GaAs 可饱和吸收体在 1050 nm 处的调制深度为 7.9%，非饱和损耗为 3.3%。在激光应用中，GaAs MW 已被有效地用作可饱和吸收器，以在 Yb 体激光器中实现 Q 开关和双波长同步锁模操作。这些结果不仅为大直径半导体线的使用提供了新的见解，而且还扩大了需要带隙调谐的应用的潜力。