Study Of Frequency Stabilizing And Phase Locking For Diode Lasers

Recently, atomic frequency standard, gravitational wave detection, matter wave interferome-try, optical interferometry, ultra cold atom, quantum information and precision spectroscopy have been well developed. All of these fields employ the technology of laser phase and frequency stabi-lization as a basic key tool. This paper takes external cavity diode laser as an example to distribute the technology above. The paper first analyzes the feasibility of laser phase and frequency lock from physical basis. external cavity diode lasers supply three interfaces, temperature, PZT and current, for output frequency controlling. These interfaces can response wide band controlling signals, making the lasers behaving as an electronic vantage controlled oscillator. Demands of laser phase and frequency lock are met. Phase locked loops in electronics mentioned in the sec-ond chapter of this paper provide theoretical models and analysis approaches for laser phase lock. The third chapter summarizes laser frequency lock methods, including dichroic-lock, dither-lock and FVC-lock. Experimental apparatus and results are given out in this chapter. Dichroic-lock and FVC-lock can lock the laser line width to 200KHz. This chapter also analyzes modulation transform methods, and gives out some simulation results as reference for experiments. In the 4th chapter, there are two laser phase locking solutions described, heterodyne phase-lock and fre-quency divided lock employing digital PIDs as controllers. A minimum phase error fluctuation 0.03 rad2 is realized. Furthermore the digital PID controllers can connect with computers, then computers can control the process of phase lock, adjust parameters conveniently. It's almost a trial internationally.