CW色素レーザー分光法によるNa原子の検知限界

抄録

The possible use of tunable dye lasers as a monochromatic source in atomic absorption and fluorescence spectrometry, which is widely employed for trace element analysis, is studied. The atomic density in a sodium vapour cell is measured by four different methods using a narrow-band CW dye laser; (a) single-pass absorption measurement, (b) absorption measurement inside a Fabry-Perot resonator, (c) absorption measurement inside a dye laser cavity, and (d) resonant fluorescence measurement. The obtained detectable limit in each method is as follows; (a) 4×10⁷ atoms/cm³, (b) 2×10⁶ atoms/cm³, (c) 5×105 atoms/cm³, and (d) 3000 atoms/cm³. These values are limited by the fluctuation of laser emission. The experimental results are in good agreement with the theoretical analysis of the SN ratio under the condition of ideal monochromatic radiation and Doppler-broadened line profile.