Coherent 420 nm laser beam generated by four-wave mixing in Rb vapor with a single continuous-wave laser

Liu Hao^{1, 2}, Yuan Jin-Peng^{1, 2, †}, Wang Li-Rong^{1, 2, ‡}, Xiao Lian-Tuan^{1, 2}, Jia Suo-Tang^{1, 2}

(a) Contour plots of the generated blue laser intensity as a function of the pump laser frequency detuning and atomic density. The white line shows the two-photon transition spectroscopy in vapor A. (b) The generated CBL power versus atomic density when the pump laser frequency is red detuned 600 MHz from ⁸⁵Rb 5D_5/2 →5S_1/2 (F = 2) transition.