Development of a 553 nm light source for Ba isotope–selective excitation using a distributed feedback (DFB) laser and a periodically poled LiNbO 3 (PPLN) waveguide

Abstract A light source for selective excitation of barium isotopes at 553 nm was developed using a distributed feedback (DFB) laser and a periodically poled LiNbO 3 (PPLN) waveguide, and the laser characteristics relevant to the excitation were measured. The fundamental output at 1107 nm from the DFB laser was approximately 86 mW, and the second harmonic generation output at 553 nm from the PPLN waveguide was 15 mW at a DFB current of 200 mA. After 4 h of operation, the output power reductions at 1107 nm and 553 nm were 0.2% and 2%, respectively, indicating stable performance. A frequency scan was demonstrated maintaining single-mode operation and good linearity. Since the developed laser system generated light with sufficient power and selectivity for barium excitation, it is suitable for use as a 553 nm light source in applications such as isotope-selective loading into ion traps, high-resolution spectroscopy, and isotope separation.