LAUSR

Abstract In order to achieve the coherent combining of two individual lasers, the relationship between two lasers should be determined. Since the phase noise is one of the primary reasons that cause the randomness of the initial phase, an optical phase-locked loop (OPLL) is employed to suppress the phase noise of the laser. To provide reliable design parameters for high performance OPLL, the statistical characteristics of laser phase noise are studied theoretically, and the influence of phase noise on laser’s coherence is analyzed. Furthermore, the working mechanism of OPLL is explained physically. The effect of parameter T and the intensity of laser phase noise on the coherence of the phase-locked laser are discussed in detail. The results show that T is related to linewidth. Specifically, when the linewidth is equal to 2MHz, T should be controlled in the ‘ns’ magnitude to achieve better locking of the laser phase.