Silicon-Based Visible/Near-Infrared Affordable Missile Warning

摘要

The concept of the refluorescent atomic filter is shown in figure 2. Only photons at the resonant frequency of the atomic transition line are absorbed; all other photons pass through the cell without interference. If the atomic vapor is optically thick on the resonance absorption line, then photons absorbed by the atoms are trapped within the optical depth the entrance window of the cell. This trapping occurs at the same wavelength independent of the angle at which the photons arrive. In the absence of quenching. these photons undergo a random walk as they are absorbed and entitled the potassium atoms.