我們建立了飽和吸收光譜系統，並以中空陰極燈做為離子源。利用此系統量測鈣離子42S1/2能階到42P1/2能階的躍遷光譜，其對應的波長為397奈米。量測訊號進一步利用鎖相放大器放大。其量測結果為受到速度交換碰撞效應影響的飽和吸收光譜。此結果顯示出中空陰極燈可作為簡易有效的397奈米波長雷射參考源。利用速度交換碰撞效應的半古典理論分析，量測譜線為一勞倫茲函數搭配高斯函數作為背景，顯示出鈣離子與緩衝氣體發生強碰撞。透過增加鎖相放大器中的頻率，我們可以有效的減少速度交換碰撞效應。另外，透過鎖相放大器的相位資訊，我們可以估計速度交換碰撞效應發生所需要的時間範圍。

We established a saturated absorption system where we used a hollow cathode lamp (HCL) as the ion source. We measured the 42S1/2 to 42P1/2 transition of calcium ion at 397 nm. The signal was amplified by a lock-in amplifier. Sub-Doppler profiles with velocity changing collision (VCC) effect of calcium ion has been measured. It shows that HCL is a simple and effective reference of 397 nm. By analyzing the fine profile by semiclassical model of VCC, it shows that the profile is a Lorentzian superimposed a Gaussian background and shows that there are strong collisions between calcium ions and buffer gas. By increasing the chopping frequency of the lock-in amplifier, we can reduce the VCC effect effectively. Besides, the phase recorded by the lock-in amplifier can provide information about time scale of VCC effect.

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