超/次辐射二次谐波产生
Super/Subradiant Second Harmonic Generation
摘要：
提出了一种有源二次谐波产生方案。该系统包括位于谐振腔中的梯形结构的$N$三能级原子。结果表明，该系统可以在超辐射或亚辐射区激光，这取决于原子的数目$N$。当N超过某个临界值时，从超辐射到亚辐射的转变以类似相变的方式发生。稳态的稳定性研究支持这一结论。
英文摘要：
A scheme for active second harmonics generation is suggested. The system comprises $N$ three-level atoms in ladder configuration, situated into resonant cavity. It is found that the system can lase in either superradiant or subradiant regime, depending on the number of atoms $N$. When N passes some critical value the transition from the super to subradiance occurs in a phase-transition-like manner. Stability study of the steady state supports this conclusion.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
