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

今年，我们使用Rb吸收线在直接频移键控（FSK）下将半导体激光器的振荡频率稳定在800 nm波长区域。我们还测量了与参考频率的频率偏差。在不同的FSK条件下，峰值保持法具有较好的稳定性。例如，一些不同的频移和占空比，在与传统的方法相比，未调制的情况下。由于半导体激光器直接调频时的热效应，直接矩形波调制不能得到完全的FSK调制。我们设计了两个简单的电路，并获得了接近完整FSK调制的调制。这种调制方式具有较好的稳定性和较小的频偏。我们也研究了用原子线饱和吸收光谱法来稳定的方法，并在今年获得了一位数以上的稳定性。我们将研究的振荡频率稳定的半导体激光器在较高的调制频率和波长为1.55微米，通过使用峰值保持方法。

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.