基于奇异点的相干完美吸收传感

Coherent Perfect Absorption Sensing Based on Exceptional Points

传感在许多领域都有十分重要的作用。基于奇异点的传感由于其在奇异点附近具有较高的灵敏度而被广泛研究。但是在弱耦合区域透反射谱线的峰或者谷并不总是严格与哈密顿量本征值的实部相对应。因此基于奇异点的传感会存在误差。这里我们通过超材料建立一个具有PT对称的系统来实现相干完美吸收并且提出一种基于奇异点的相干完美吸收谱线的传感。随参数的演变,系统在奇异点之后哈密顿量的本征值一直为实数。由于相干完美吸收需要哈密顿量的本征值为实数,因此相干完美吸收峰跟哈密顿量本征值实部是严格对应的。这种探测器避免了此前基于奇异点与透反射谱线不能对应的问题。并且对实现新型传感器具有指导作用。

Sensing plays an important role in many fields. The sensor based on the exception point has been widely studied because of its high sensitivity near the exception point. However, the peaks or valleys of the transmission and reflection lines in the weakly coupled region do not always correspond strictly to the real part of the eigenvalues of Hamiltonian. Therefore, the sensor based on the exceptional point will have error. In this paper, we establish a PT-symmetric system to achieve coherent perfect absorption by metamaterials and propose an exceptional point-based coherent perfect absorption line sensing. The eigenvalue of the Hamiltonian is always a real number after the system is at an exceptional point. Since the eigenvalue of the Hamiltonian is required to be real, the coherent perfect absorption peak corresponds strictly to the real part of the eigenvalue of the Hamiltonian. This kind of detector avoids the problem that previously based on the exception point can not correspond with the transmission and reflection spectrum line. And it has the guiding function to realize the new type sensor.