By means of laser spectroscopy and optogalvanic detection, we searched for unknown spectral lines of atomic lanthanum (La I) in the red region of the visible spectrum (6900–6200 Å). Most of the discovered lines could be interpreted as transitions between known energy levels due to wavelength and observed hyperfine structure pattern. For lines which we could not classify we searched for laser-induced fluorescence in order to identify at least one level involved in the transition. In this way we discovered 25 energy levels of La I having even parity. For two levels we could improve the accuracy of energy and hyperfine structure constants. These 27 levels classify 213 spectral lines.

通过激光光谱和光电检测，我们在可见光谱的红色区域（6900–6200Å）中搜索了原子镧（La I）的未知光谱线。大多数发现的谱线可以解释为由于波长和观察到的超精细结构模式而在已知能级之间的转变。对于我们无法分类的品系，我们搜索了激光诱导的荧光，以识别至少一个涉及过渡的水平。这样，我们发现La I的25个能级具有均等的平价。对于两个级别，我们可以提高能量和超精细结构常数的精度。这27个等级将213条光谱线分类。