Wavelength Stabilization of a Semiconductor laser in High-Speed Modulation Using Saturated Absorption Spectroscopy of Atomic Lines

今年，我们利用Rb吸收线在直接频移键控(FSK)下稳定了半导体激光器在800 nm波段的振荡频率。我们还测量了与参考频率的频率偏差。与传统的非调制情况相比，峰值保持法在不同的FSK条件下，即不同的频移和占空比下，已经观察到了更好的稳定性。在半导体激光器直接频率调制中，由于热效应的影响，矩形波直接调制不能给出完全的FSK调制。我们设计了两个简单的电路，得到了接近于完全FSK调制的调制。这种调制提供了更好的稳定性和更小的频率偏差。我们还研究了利用原子线的饱和吸收光谱进行稳定化的方法，并在今年获得了一位数以上的稳定性。我们将用峰值保持法研究半导体激光器在更高的调制频率和1.55微米波长下的振荡频率稳定性。

We stabilized the oscillation frequency of a semiconductor laser at 800 nm wavelength region under direct frequency shift keying (FSK) using the Rb absorption lines in this year. We also measured the frequency deviation from the reference frequency. The better stability had already been observed in the peak-hold method under some different FSK conditions, i. e., some different frequency shifts and duty ratios, in comparison with the traditional method of the unmodulated case. The direct rectangular weve modulation does not give the complete FSK modulation because of the thermal effect at a semiconductor laser direct frequency modulation. We devised two simple circuits and obtained the modulation close to the complete FSK modulation. This modulation provided the better stability and the less frequency deviation. We also investigated the method using the saturated absorption spectroscopy of atomic lines for the stabilization and obtained more than one digit better stability in this year. We will investigate the oscillation frequency stabilization of the semiconductor laser at the higher modulation frequency and at the wavelength of 1.55 mum by using the peak-hold method.