High pressure chemical vapor deposition (HPCVD) has shown to be a promising method for producing Cr²⁺:ZnSe and Fe²⁺:ZnSe mid-IR optical fiber lasers. The oxidation state of the dopants and their spatial homogeneity are critical for the characterization of effective fiber laser performance; however, this is challenging for small fiber cores and small doping concentrations. We demonstrate using synchrotron micro X-ray fluorescence (XRF) mapping to study the distribution of the dopants throughout the fiber cross-sections. Furthermore, we study the local chemical environment of these unique fiber structures using micro X-ray near edge absorption spectroscopy (XANES). Our study reveals that transition metal doped ZnSe deposited using HPCVD has nanoscale dopant aggregation although the material is chemically identical to the commercially produced diffusion doped laser crystals, as indicated by the presence +2 oxidation state of the dopants. This work demonstrates the power of synchrotron-based X-ray techniques for use as metrology tools for improving the performance of laser materials in fiber geometry.

中文翻译：

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高压CVD生长TM ²⁺：ZnSe光​​纤的同步辐射X射线计量掺杂物分布和氧化态。

高压化学气相沉积（HPCVD）已被证明是生产Cr ²⁺：ZnSe和Fe ²⁺的有前途的方法：ZnSe中红外光纤激光器。掺杂剂的氧化态及其空间均匀性对于表征有效光纤激光器性能至关重要。然而，这对于小纤芯和低掺杂浓度而言是具有挑战性的。我们演示了使用同步加速器X射线荧光（XRF）映射来研究整个纤维截面中掺杂物的分布。此外，我们使用微X射线近边缘吸收光谱（XANES）研究了这些独特纤维结构的局部化学环境。我们的研究表明，使用HPCVD沉积的过渡金属掺杂的ZnSe具有纳米级的掺杂剂聚集，尽管该材料在化学上与商业生产的扩散掺杂的激光晶体相同，如掺杂剂的存在+2氧化态所示。