The optical fiber geometry is known for rugged, high power laser sources that are preferred for many applications, but is typically limited to the visible and near-infrared regions of the electromagnetic spectrum due to the transmission limits of silica (< 2 µm). This wavelength range could be extended into the mid-infrared using transition metal doped, crystalline II-VI optical gain media, but these materials cannot be fabricated into optical fibers using conventional glass drawing methods. An in-situ high pressure chemical vapor deposition method for the fabrication of silica-cladded $\textrm {ZnSe}$ fiber cores uniformly doped with $\textrm {Cr}^{2+}$ is reported. Optical pumping experiments reveal that these doped fibers exhibit threshold behavior and thus function as mid-infrared optical fiber lasers. Finite element calculations show that undesirable thermal effects common in bulk II-VI crystals are mitigated in the fiber geometry.

中文翻译：

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铬掺杂硒化锌光纤激光器

光纤的几何形状对于坚固耐用的高功率激光源是众所周知的，对于许多应用而言，这种光源是首选的，但是由于二氧化硅的传输限制（<2 µm），通常将其限制在电磁光谱的可见光和近红外区域。使用过渡金属掺杂的晶体II-VI光学增益介质可以将该波长范围扩展到中红外，但是使用常规的玻璃拉伸方法无法将这些材料制成光纤。一种原位高压化学气相沉积方法，用于制备均匀掺有$ \ textrm {Cr} ^ {2 +} $的二氧化硅包覆的$ \ textrm {ZnSe} $纤维芯被报道。光泵浦实验表明，这些掺杂的光纤表现出阈值行为，因此可以用作中红外光纤激光器。有限元计算表明，在纤维几何形状中，II-VI型块状晶体常见的不良热效应得以缓解。