[01] Tomoyuki Uehara, Department of Communications Engineering, National Defense Academy of Japan, Yokosuka, Japan. [02] Shinya Maehara, Faculty of Engineering, Niigata University, Niigata, Japan. [03] Kohei Doi, Faculty of Science, University of Toyama, Toyama, Japan. [04] Toshiya Nimonji, YMP-Mundus Corporation, Osaka, Japan. [05] Takahiro Saito, Graduate School of Science and Technology, Niigata University, Niigata, Japan. [06] Hideaki Arai, Graduate School of Science and Technology, Niigata University, Niigata, Japan. [07] Takashi Sato, Faculty of Engineering, Niigata University, Niigata, Japan. [08] Yasuo Ohdaira, Faculty of Engineering, Niigata University, Niigata, Japan. [09] Shuichi Sakamoto, Faculty of Engineering, Niigata University, Niigata, Japan. [10] Masashi Ohkawa, Faculty of Engineering, Niigata University, Niigata, Japan.

A stable microwave source using frequency stabilized diode lasers was developed. The Doppler-free spectra of Rb atoms produced by saturated absorption spectroscopy were used to obtain highly-sensitive control signals and lock the frequency of diode lasers to it. The beat frequencies between two independently stabilized diode lasers were 1.2 GHz and 2.9 GHz. The fluctuations in beat frequencies were 40 kHz and 400 kHz respectively in the best stability.

Frequency Stabilization, Diode Laser, Saturated Absorption Spectroscopy, Rubidium Absorption Line, Microwave

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