Shot noise

<p><b>shot noise:</b> The <a href="http://www.atis.org/tg2k/_noise.html">noise</a> caused by random fluctuations in the motion of charge carriers in a conductor. <i>Note:</i> There is often a minor inconsistency in referring to shot noise in an optical <a href="http://www.atis.org/tg2k/_system.html">system</a>: many authors refer to shot noise loosely when speaking of the mean square shot <a href="http://www.atis.org/tg2k/_noise_current.html">noise current</a> (amperes²) rather than <a href="http://www.atis.org/tg2k/_noise_power.html">noise power</a> (watts).</p> <p>果然是散粒噪声，看来我的直觉不错:P</p> <p><hr /><br /> <h2>Photon shot noise</h2> <p><b>Authors:</b> <br /><a href="http://arxiv.org/find/cond-mat/1/au:+Beenakker_C/0/1/0/all/0/1">C.W.J. Beenakker</a>, <br /><a href="http://arxiv.org/find/cond-mat/1/au:+Patra_M/0/1/0/all/0/1">M. Patra</a></p> <p><b>Comments:</b> 11 pages, 4 figures (caption to figure 3 corrected)</p> <p><b>Subj-class:</b> Mesoscopic Systems and Quantum Hall Effect</p> <p><b>Journal-ref:</b> Mod.Phys.Lett.B 13, 337 (1999)</p> <p><b>DOI:</b> <a href="http://dx.doi.org/10.1142/S0217984999000439">10.1142/S0217984999000439</a></p> <blockquote><p>A recent theory is reviewed for the shot noise of coherent radiation<br />propagating through a random medium. The Fano factor P/I (the ratio of the<br />noise power and the mean transmitted current) is related to the scattering<br />matrix of the medium. This is the optical analogue of Buttiker's formula for<br />electronic shot noise. Scattering by itself has no effect on the Fano factor,<br />which remains equal to 1 (as for a Poisson process). Absorption and<br />amplification both increase the Fano factor above the Poisson value. For strong<br />absorption P/I has the universal limit 1+3f/2 with f the Bose-Einstein function<br />at the frequency of the incident radiation. This is the optical analogue of the<br />one-third reduction factor of electronic shot noise in diffusive conductors. In<br />the amplifying case the Fano factor diverges at the laser threshold, while the<br />signal-to-noise ratio I^2/P reaches a finite, universal limit.</p></blockquote> <p> <h3>Full-text: <a href="http://arxiv.org/ps/cond-mat/9905024">PostScript</a>, <a href="http://arxiv.org/pdf/cond-mat/9905024">PDF</a>, or <a href="http://arxiv.org/format/cond-mat/9905024">Other formats</a></h3>