双带型光子晶体中双V型四能级原子自发辐射谱中的黑线研究

The dark lines in the spontaneous emission spectrum of a double V-type four-level atom in double-band photonic crystal

研究了双带型光子晶体中双V型四能级原子自发辐射的辐射谱.双V型四能级原子同时与真空热库和双带型光子晶体热库耦合.研究发现双V型四能级原子自发辐射谱中有三种不同原因可能引起的黑线:第一种是由于量子干涉效应;第二种是由于各向同性光子晶体带边处态密度具有奇异性;第三种是真空场中的量子干涉和光子晶体禁带内态密度为零共同作用的结果.通过移动光子晶体的带边位置,在各向同性光子晶体带边引入光滑因子,以及在光子晶体中引入缺陷等对这三种黑线的影响,对上述结果进行了分析和讨论.

The spontaneous emission spectrum of a double V-type four-level atom in a double-band photonic crystal is investigated. The double V-type atom is respectively coupled by the free vacuum modes and the photonic band gap modes. There are three types of dark lines in the spectrum：the first type originates from the quantum interference,the second type originates from the singularities of the density of states at the isotropic photonic band edges,and the third type originates from the quantum interference in the vacuum modes and zero density of states in the band-gap of photonic crystal. The causes leading to these three types of dark lines are investigated by varying the detuning of the atomic transitions from the band edge,by introducing smoothing parameter to eliminate the singularity of the density of states at the isotropic photonic band edges,and by introducing defect modes in the band gap of the photonic crystal.