The parametric four-wave mixing (4WM) process responsible for the generation of coherent blue light in alkali vapors is a self-seeded process which starts by population inversion and amplified spontaneous emission (ASE). Lately, attention has been turned toward frequency up- and down-conversion in alkali vapors, using relatively low pump powers with CW diode lasers. In this Letter, we investigate the interplay between ASE and 4WM in rubidium (Rb) vapors by studying the mid-infrared (mid-IR) radiation emitted in the forward direction at 5.23 μm. We show that the ASE can be suppressed by 4WM in the CW regime. Thus, we demonstrate the generation of coherent mid-IR light at 5.23 μm in hot Rb vapors via parametric 4WM.

中文翻译：

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在碱蒸汽中通过参量四波混合产生相干的中红外光

负责在碱蒸汽中产生相干蓝光的参量四波混合（4WM）过程是一种自种过程，该过程从种群反转和放大的自发发射（ASE）开始。最近，注意力转向了碱蒸汽中的频率上变频和下变频，这是通过使用相对较低的泵浦功率和连续波二极管激光器来实现的。在这封信中，我们通过研究5.23μm正向发射的中红外（mid-IR）辐射，研究了ASE和4WM在rub（Rb）蒸气中的相互作用。我们表明，在连续波系统中，ASE可以被4WM抑制。因此，我们证明了通过参数4WM在热Rb蒸气中以5.23μm的波长产生相干的中红外光。