AI 中文总结
该研究提出采用常规耦合的级联线性放大器，通过降低光束特性要求，理论上可实现相干性随总源激发数指数缩放，两个放大器即可突破标准的平方级缩放限制。
AI 中文摘要
标准激光束的光子简并度（即相干性）$\u2102$最多为$8\mu^2$，其中$\u03bc$是激光本身的光子数。即使是量子工程激光器，若需产生具有标准统计特性的光束，其相干性也有限，按$\u03bc^4$缩放，且这类激光器（尚未实现）需要非常规的增益和输出耦合机制。本文提出一种提升$\u2102$的不同路径：采用常规耦合的级联线性放大器，通过降低对光束特性的要求，该方法理论上可实现$\u2102$按$\u03bc$的指数缩放，其中$\u03bc$是所有放大器的总源激发数，两个放大器即可超过标准的$\u03bc^2$缩放。
英文摘要
A standard laser beam has photon degeneracy, or coherence, $\mathfrak{C}$, of at most $8μ^2$, where $μ$ is the number of photons in the laser itself. Even quantum-engineered lasers, if required to produce a beam with the standard statistical properties, have limited coherence, scaling as $μ^4$. Moreover, such lasers (still unrealised) require very unconventional gain and output-coupling mechanisms. Here, we propose a different path to increasing $\mathfrak{C}$: cascaded linear amplifiers, with conventional couplings. By dropping the requirement on the beam's properties, this approach can, in theory, achieve $\mathfrak{C}$ scaling exponentially in $μ$. Here $μ$ is the total source excitation number, across all the amplifiers. Two amplifiers suffice to surpass the standard $μ^2$ scaling.
Comments29 pages, 5 figures
