本論文主要在解決當進行熱原子產生單光子實驗時，窄線寬Etalon的中心頻率隨著時間飄動的問題，我們利用PDH的方式將雷射鎖頻於Etalon，讓雷射頻率隨著Etalon飄動，維持雷射通過Etalon的穿透率在一定範圍內後，再降低漏光進單光子偵測器以免造成雜訊。
　　研究主要分為兩部分，第一部分為PDH 鎖頻，其中，第1章到第3章介紹PDH的原理與得到最佳Etalon光譜的條件，第4章到第6章介紹實驗上如何最佳化PDH光譜與了解並減少儀器造成的雜訊，最後得到鎖頻短時間與長時間的結果。
　　第二部分為，鎖頻完後，第7章到第11章介紹實驗上嘗試幾種降低漏光的方法，第12章則對於先前幾種衰減方式在理論上從入射光進Etalon與從Etalon反射的光做分析整理後，預測不同透鏡組和得到的反射光的行為與不同方式得到的衰減率。

This thesis is mainly to solve the problem that the center frequency of the narrow linewidth Etalon fluctuates with time when performing the single photon experiment of hot atoms. We use the PDH method to lock the laser frequency to Etalon, so that the laser frequency fluctuates with Etalon , After maintaining the penetration rate of the laser through Etalon within a certain range, reduce the light leakage into the single photon detector to avoid noise.
　　The research is mainly divided into two parts. The first part is PDH frequency locking. Among them, Chapter 1 to Chapter 3 introduce the principle of PDH and the conditions for obtaining the best Etalon spectrum, and Chapter 4 to Chapter 6 introduce how to optimize the experiment. PDH spectrum and understand and reduce the noise caused by the instrument, and finally get the result of short-time and long-time frequency lock.
　　The second part is that after the frequency lock is completed, Chapter 7 to Chapter 11 introduce experimental methods to reduce light leakage. Chapter 12 theoretically introduces the previous attenuation methods from incident light into Etalon and light reflected from Etalon. After analysis and finishing, predict the behavior of different lens groups and the resulting reflected light and the attenuation rate obtained in different ways.

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