Green laser pointer could also be used as a weapon

Inversion level material in high energy particle density greater than low-level particle number density, known as the absolute temperature inversion to take "absolute temperature to take the" negative "value is not possible to use external energy excitation, the low level of particles to high energy level transitions in large numbers, with foreign energy incentives, so that low levels of particles to high energy level transitions in large numbers, to break the atomic-like system to establish a thermal equilibrium distribution of particles of inversion. state, to establish the number of reverse particle distribution. pump (or pump) : the supply of low-level particle energy to the process of transition to the high energy level. pump (or pump): the supply of low-level particle energy to the process of transition to the high energy level. The light of green laser pointer is generated by material.Atomic energy level system: time to low levels of spontaneous transition particle number: spontaneous emission coefficient of the particle energy levels characteristic parameters of the system is a constant. Is a constant. Einstein spontaneous emission coefficient, Einstein spontaneous emission coefficient dN 21 A21 = N 2 dt physical meaning: in the level of each particle in the unit time probability of spontaneous emission. Physical meaning: each particle in the E2 level in the unit time probability of spontaneous emission. Magnitude is about -8 seconds, said, E2 level on the occurrence of spontaneous emission of each particle probability 1 / 2. 1 spontaneous emission of light spontaneous emission light generated § 1-2 of the excited state lifetime of the laser: high energy exponential decrease of the number of particles, reducing the speed determined by the A 21. The light difference between green laser pointer and common light is the lightening micromechanism.Excited state lifetime average time t, dN21 atoms have stayed on in over 2 levels, the total time spent for the time, atoms have stayed on the E level before, the sum of all the atoms of life is the spontaneous emission transition probability of the countdown. Is the inverse of the spontaneous emission transition probability. Is the number of excited particles decay when the initial particle number N times the time required. τ is the number of excited particles decay when the initial number of particles 20 to 1 / e times the time required. / Times the time required for 17 1. Spontaneous emission of light spontaneous emission light generated § 1-2 laser transition to the more low-level spontaneous situations: the spontaneous transition to the more low-level cases: if the atomic energy level E of the low level of m for a low level of spontaneous transition to spontaneous transition,The light wave sent by green laser pointer is with same frequency, direction, polarization state and strict phase relation. if the atomic energy level n on a low level to a spontaneous transition, and also to the low level of D for transition probabilities of transition to other forms of non-radiative transition) of the other form of transition (for the transition probability for the transition to other forms of (non-radiative transition), the excited state En, the average life expectancy of the average life of excited state energy levels of atoms on the low level of m, respectively, to be where is the energy level En the atoms to a low level of probability for spontaneous emission transition. spontaneous emission transition probability.For those differences, light of green laser pointer has the features of high strength, good monochromaticity and well phase relation. D nonradiative transition El atomic spontaneous emission transition probability greater the shorter the life of the excited state of atomic spontaneous emission transition probability greater , the shorter excited state lifetime of 18 (2) absorption of light by stimulated absorption of light by stimulated emission assuming two energy levels E to meet the transition selection rules.