Research On A Frequency Stabilization System For The Ecdl And Its Applications In The Atomic Interferometry

In recent years, the performances of narrow linewidth tunable external cavity diode lasers (ECDLs) have been increasingly improved, while the prices are more competitive than other lasers, so it is widely used in the fields of metrology applications, optical communications, high-resolution spectroscopy, and the rest of fundamental physics. When a recent study of cold atoms becomes a hot technology, especially, the prospects for its application are further expanded. In this paper, for the atomic inertial technology research needs, we carried out the development of a laser stabilization system based on the theory of saturated absorption and phase-sensitive detection technique, in order to replace expensive imported equipments.First of all, we have analyzed the frequency variation model of ECDLs and its influencing factors, and we determined the program of saturated absorption spectra of frequency stabilization based on the phase-sensitive detection by comparing various methods of frequency stabilization. Furthermore, we analyzed the principle of frequency discrimination and its influencing factors.Secondly, we made an overall design for the system and established a mathematical model of the servo control system of frequency stabilization. The system was synthesized and corrected into a promising frequency response model with good control characteristics. Besides, interpretation of the principle and progress of frequency-locking system was simulated on computer, to verify the feasibility of the system, as the guidance of the circuit design.Thirdly, the circuits of the frequency stabilization system have been designed and produced: local oscillator circuit, optical detection and signal conditioning circuit, phase-sensitive detection circuit, servo-control correction circuit, output driver circuit, and other auxiliary circuits. Integration and package of the circuit system were completed to achieve self-developed equipments dedicated frequency stabilization. Finally, the performances of the system applied to the ECDLs at 780nm were tested by using of ⁸⁷Rb atomic absorption spectrometry. The experimental results show that the system is very robust: the laser frequency drift is less thanΔυ_p-p≈1.5MHz and the frequency line-width isΔυ_rms≈0.37MHz in 2.3 seconds. The Allan deviation is ⁸×10^-11 at 1s averaging time.