Optogalvanic spectroscopy as well as laser-induced fluorescence spectroscopy were applied in order to find new energy levels of atomic lanthanum. A hollow-cathode lamp and a tuneable continuous wave titanium-sapphire laser in the wavelength range from 750 nm to 850 nm were used for the measurements. Three energy levels of even parity with small values of total angular momentum quantum number J were discovered: 38 519.18 cm${}^{-1}$ with $J=1/2,$ 40 392.80 cm${}^{-1}$ with $J=3/2,$ and 42 191.24 cm${}^{-1}$ with $J=3/2$. The existence of these three levels was confirmed by laser excitations of several spectral lines as well as by spectral lines from a Fourier transform spectrum. Magnetic dipole hyperfine structure constants of the three new levels were determined from fits of the experimental spectra of the laser lines.

为了发现原子镧的新能级，应用了光电子能谱以及激光诱导的荧光能谱。使用中空阴极灯和波长范围为750 nm至850 nm的可调谐连续波钛-蓝宝石激光器进行测量。发现了三个平均能级且平均角动量量子数J小的能级：38 519.18 cm${}^{-\mathrm{1个}}$ 与 $Ĵ=\mathrm{1个}/2，$ 40392.80厘米${}^{-\mathrm{1个}}$ 与 $Ĵ=3/2，$ 和42 191.24厘米${}^{-\mathrm{1个}}$ 与 $Ĵ=3/2$。这三个水平的存在通过激光激发多条光谱线以及傅立叶变换光谱的光谱线来确认。从激光线的实验光谱拟合确定了三个新水平的磁偶极超细结构常数。