Abstract—

The influence of fundamental noises of a diode laser and a photodetector on the registration of absorption spectra by diode laser spectroscopy (DLS) has been studied. It is shown that the diode laser noise is maximal at pump currents close to the threshold value. At currents significantly exceeding the threshold values, the signal-to-noise ratio tends to a constant. When the recorded radiation flux increases, the relative noise of the photodiodes decreases and at sufficiently high values becomes negligible compared to the diode laser noise. Thus, it is experimentally shown that the minimum achievable limits of detection of various substances in diode laser spectroscopy are determined by the noise of the diode laser itself. The obtained results have an important application value; they can be used to design analytical equipment for measuring low concentrations of gaseous substances.

中文翻译：

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二极管激光光谱学中的基本噪声

摘要-

研究了二极管激光器和光电探测器的基本噪声对二极管激光器光谱法（DLS）吸收光谱配准的影响。结果表明，在泵浦电流接近阈值时，二极管激光噪声最大。在电流明显超过阈值时，信噪比趋于恒定。当所记录的辐射通量增加时，光电二极管的相对噪声降低，并且与二极管激光噪声相比，在足够高的值下可以忽略不计。因此，实验表明，在二极管激光光谱中检测各种物质的最小可达到极限由二极管激光器本身的噪声确定。所得结果具有重要的应用价值。