本研究著重於提升時間解析激發－探測量測系統的訊噪比，透過超快雷射之鎖模狀態觀測、即時影像監控激發探測光束之重合狀態、光偵測器參數最佳化，以及調整正交之偏振狀態等，期望找出適當最佳化參數，以獲得時間解析激發－探測反射率量測的最佳訊號。以 GaAs 晶片做為最佳化的實驗樣品，激發光與探測光強度分別僅需要 50 mW 及 1 mW 之低功率操作，目前已可將訊噪比提升至 50 左右。

SNR is an important indicator for time-resolved pump-probe system. We focus on improvement of SNR in this study. After optimization, the SNR of time-resolved pump-probe system for GaAs sample is about 50 in this system.The optical power for pump and probe beam is only 50 mW and 1 mW, respectively.