• 作者： 彭保仁; 易台生
• 作者服務機構： 中央大學物理系
• 中文摘要： 以單一雷射光束入射至鈉蒸氣中，我們觀察到兩條真空紫外光輻射線。雷射光源乃是脈衝式染料雷射。雷射波長調至鈉原子3s-4d雙光子共振波長578.7奈米附近。我們發現193奈米輻射乃是入射雷射光子的三次諧波放射。至於179奈米輻射則被檢定為四波混合所發生。其混合的機制如下： ω179nm = 2ωL + ω465.7nm其中ω179nm是179奈米輻射光子的頻率，ωL是雷射光子的頻率，ω465.7nm是465.7奈米輻射光子的頻率。我們使用一個簡單的計算模型求出179奈米輻射線強度及軸向相匹配條件，以便進一步解釋這條輻射線的生成機制。理論分析顯示相位匹配條件對輻射線訊號強度有重要影響。
• 英文摘要： We observed two vacuum ultraviolet emissions in sodium vapor when it was irradiated by a single laser beam.The laser beam source was a pulsed dye laser with an output wavelength tuned near 578.7nm, which is the sodium 3s-4d two-photon resonance transition wavelength. We recognize that 193nm emission is the third harmonic generationof the input laser photon while the 179nm emission is identified as a four-wave mixing generated radiation. Its mixingscheme is ω179nm = 2ωL + ω465 7nm,where ω179nn is the 179nm emission photon frequency, ωL is the laser photon frequency, and ω465 7nm is the 465.7nmemission photon frequency. A simple model calculation of the emission intensity and axial phase match condition isconducted to further explain the generation mechanism of these vacuum ultraviolet emissions. Theoretical analysisindicates that the phase match condition has dominant influence on the emission signal intensities.
• 中文關鍵字： vacuum ultraviolet emission; sodium vapor; four-wave mixing
• 英文關鍵字： --