中国物理B ›› 2004, Vol. 13 ›› Issue (3): 353-358.doi: 10.1088/1009-1963/13/3/016
吴大进1, 曹力2, 张莉3
Zhang Li (张莉)ab, Cao Li (曹力)acd, Wu Da-Jin (吴大进)cd
摘要: By means of the unified coloured noise approximation and phase lock, we study in this paper the stationary intensity distribution of the single-mode laser cubic model driven by coloured pump noise with cross-correlation between the real and imaginary parts of the quantum noise. We present a thorough discussion of how the cross-correlation λ_q between the real and imaginary parts of the quantum noise and the self-correlation time τ of the pump noise determine the behaviours of the mean intensity 〈I〉 and variance λ_2 (0) for both below and above the threshold operation, and many new phenomena are discovered. When the laser is operated above the threshold, increasing the cross-correlation intensity λ_q makes the 〈I 〉-τ curves exhibit a "re-entrant phase transition". Whether the laser is above or below the threshold, the whole 〈I 〉-τ curve moves down as λ_q increases; however, when λ_q=1 (perfect cross-correlation), the curve abruptly runs up. A nonzero value of cross-correlation time τ (τ≠0) leads to the entire λ_2(0)-p′ curve being suppressed (here p′ is the pump noise intensity). This indicates the increasing precision of the laser beam due to the existence of the self-correlation time τ. The behaviour of the λ_2 (0)-p′ curve as a function of λ_q is similar to that of the 〈I 〉-τ curve against λ_q: that is, whether the laser is above or below the threshold, the λ_2 (0)-p′ curve moves up as λ_q increases; however, when λ_q=1, the curve suddenly moves down. Through the study in this paper, we can find a way to optimize for output laser intensity.τ
中图分类号: (Quantum fluctuations, quantum noise, and quantum jumps)