The linearity of the responsivity of a silicon carbide photodetector in the deep-ultraviolet has been studied using a variant of the so-called intensity-ratio method in view of the implementation of low-uncertainty Doppler-broadening thermometry in mercury vapours. To this purpose, coherent radiation at the wavelength of 254 nm has been produced by means of nonlinear mixing of two visible laser beams in a β-barium borate crystal. The linearity has been quantified as a function of the exposure power, variable in the range between 50 and 300 nW. It is shown that possible deviations from linearity are within the uncertainty of 4 10-5 (corresponding to one standard deviation). Such a performance makes the detector well suitable for the thermometric application.

中文翻译：

---

深紫外光谱区碳化硅光电二极管的线性度：对多普勒展宽温度测量的影响

鉴于在汞蒸气中实施低不确定性多普勒展宽温度测量法，已使用所谓的强度比方法的变体研究了碳化硅光电探测器在深紫外线中响应度的线性。为此，通过在 β-硼酸钡晶体中非线性混合两束可见激光束，产生了波长为 254 nm 的相干辐射。线性已被量化为曝光功率的函数，在 50 到 300 nW 范围内可变。结果表明，可能的线性偏差在 4 10-5 的不确定度内（对应于一个标准偏差）。这种性能使检测器非常适合测温应用。