本論文利用聲光調制器及差異光譜法做無頻率調制1.5 μm外腔半導體雷射穩頻於乙炔分子的研究。實驗上，我們利用現有的80 MHz驅動頻率的聲光調制器，將第零階與第一階繞射光導入乙炔吸收室，利用差異光譜法，獲得譜線吸收訊號。同時以此吸收訊號做為誤差訊號，藉以穩頻雷射。相對穩定度可至1 × 10-8以下。使用聲光調制器來做無頻率調制的好處為沒有穩頻後之輸出頻率具有頻率調制的缺點。 理論上我們也探討在各種不同聲光調制器驅動頻率之下的穩頻效果。 In this thesis, we investigate the modulation-free C2H2 frequency-stabilized 1.5 μm external cavity diode laser with an external acousto-optic modulator. Experimentally, we use an external acousto-optic modulator (AOM, 80 MHz). The zero-order beam and the first-order beam pass through a C2H2 Cell and are sent into a balanced detector simultaneously, and we get the absorption signal for frequency stabilization. The frequency stability is better than 1 × 10-8. The advantage of using AOM in this study is that it can provide a frequency-stabilized output without frequency dithering. In our study, we also study the effect of AOM driven with different frequency to optimize the experimental condition theoretically.
