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Moments of the intensity of a single-mode laser driven by coloured pump noises with a cross-correlation between the real and imaginary parts of the quantum noise
Zhang Li (张莉), Cao Li (曹力), Wu Da-Jin (吴大进)
Chinese Physics, 2004, 13 (3):
353-358.
DOI: 10.1088/1009-1963/13/3/016
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 $\lambda_q$ between the real and imaginary parts of the quantum noise and the self-correlation time $\tau$ of the pump noise determine the behaviours of the mean intensity 〈I〉 and variance $\lambda_2$ (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 $\lambda_q$ makes the 〈I〉－$\tau$ curves exhibit a "re-entrant phase transition". Whether the laser is above or below the threshold, the whole 〈I〉－$\tau$ curve moves down as $\lambda_q$ increases; however, when $\lambda_q$=1 (perfect cross-correlation), the curve abruptly runs up. A nonzero value of cross-correlation time $\tau$ ($\tau$≠0) leads to the entire $\lambda_2$(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 $\tau$. The behaviour of the $\lambda_2$ (0)－p′ curve as a function of $\lambda_q$ is similar to that of the 〈I 〉－$\tau$ curve against $\lambda_q$: that is, whether the laser is above or below the threshold, the $\lambda_2$ (0)－p′ curve moves up as $\lambda_q$ increases; however, when $\lambda_q$=1, the curve suddenly moves down. Through the study in this paper, we can find a way to optimize for output laser intensity.
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