Gain Narrowing in Few-Atom Systems
Using a density matrix approach, we study the simplest systems that display both gain and feedback: clusters of 2 to 5 atoms, one of which is pumped. The other atoms supply feedback through multiple scattering of light. We show that, if the atoms are in each other's near field, the system exhibits large gain narrowing and spectral mode redistribution. The observed phenomena are more pronounced if the feedback is enhanced. Our system is to our knowledge the simplest exactly solvable microscopic system which shows the approach to laser oscillation.
This paper analyses the causationes that influence the precision of the weighing system.Introduces the characteristics of the chip ADS1230 and designing of hardware circuit in weighing system.This design uses the most extensive and mature technology AT89C51 chip microcontroller and the resistance strain weighing sensor chip.The system has many characteristics-rapid weighing,exact and steady data,ease using,high anti-jamming ability etc.