腔內倍頻綠光雷射的回授控制與功率穩定性之研究

Abstract

由於腔內倍頻綠光雷射易受晶體溫度及機械震動影響，使得綠光的輸出功率有大幅度的變動，造成應用上受到限制；為得到穩定的綠光雷射，本實驗採用光回授控制系統來穩定綠光雷射的輸出。在光回授控制系統中，我們發現分光鏡的分光比必須不能隨著雷射入射角或偏振的變化而改變，在此要求之下進行光回授控制，可得到在8小時的操作時間，綠光雷射的不穩定度由±7.31%改善至±0.82%。

The output fluctuations of intracavity frequency doubled diode-end-pumped Nd:YVO4 laser arise from temperature of nonlinear crystal and mechanical vibration. The instability restricts the application of the green laser. In order to stabilize the output power, we use optical feedback control system to control the laser. However, we discover that the reflectance of beam splitter cannot vary with the direction and polarization of laser. We improve the instability from ±7.31% to ±0.82% in the measurement of 8 hours. Obviously, we obtain a more stable laser by using optical feedback control system.