It is the first step for the workshop of green laser pointer to take
The energy of the particle will be increased to E2 = E1 + hr21 (h) said that the Planck constant), the particle transition from the low energy level E1 to the high energy level E2, the process is called stimulated absorption, while the external light energy is absorbed, so that Optical weakened. Particles into a line transition is not spontaneous, to rely on external photons stimulate. Particles can absorb a photon sent, have to depend on the nature of the two energy levels (E1 and E2) and close to the particle about the number of photons. The other direction, phase, without any restrictions. Spontaneous emission process. Spontaneous emission process. Spontaneous radiation in a high energy level of the particles is very unstable, can not long stay in the high energy level. It can blend the relationship between the purchase and supply of  green laser pointer .
Particles in the high energy level E2 rapid transition to low energy levels E1, while the form of photons release energy hr21 = E2-E1 (hr21 photon frequency). This process are not subject to the role of the outside world is completely spontaneous. Generated by the light a certain regularity, phase, and direction are inconsistent. Is not monochromatic. And by the radiation emitted light, the phase and the opposite direction. This form of light radiation, called the spontaneous radiative transition. But does not produce light radiation transition in the transition process, but they are mainly based on the thermal movement of energy consumption in the form, that is, non-radiative transition. Spontaneous radiation characteristics. The technology of  green laser pointer  has to be increased to a higher level.
Each particle transitions are spontaneous, carried out in isolation, that is, independent of each other without contact. Of photons disorganized and no regularity. Particles on one. Base level particles are excited to E2 level in the particles on the energy level E2 particle transition to a low energy level E1 on the Lord of the photon emitted by stimulated emission of radiation characteristics of 1.3 stimulated the characteristics of radiation by stimulated emission of radiation it is excited by the opposite process of absorption of particles in high energy level, in a certain frequency r21 photon induced, from where the original level E2, emit identical photons with external photon, both a total of two photons to produce a photon (before and after the stimulated) so that the original reduction in energy △ E = hr21. The supply management of  green laser pointer  has been enhanced.
Particle transition to the high energy level on the low energy level E1 of this process called stimulated emission. The characteristics of stimulated emission itself is not a spontaneous transition, but by the stimuli of external photons. Thus exactly the same as the frequency of the particles released from the photon with the original photon direction of propagation, phase and polarization, can not distinguish which one is the original photon, which is generated by the excitation photons by stimulated emission of radiation due to optical radiation is proportional to the energy and photon number of cases, therefore, stimulated emission, optical double the radiation energy increases. Wave point of view, set the external photon is a wave by stimulated emission of photons for another wave, due to the phase of two waves, vibration direction, the direction of propagation and the same frequency. The material of  green laser pointer  is being purchased.
The two waves together, the energy increases the double, that is, be amplified by stimulated radiation light waves. External photon amount is more and more excited by the number of particles, the greater the resulting photon, the higher the energy. (1) in particle energy level E2. Particle transition to the low energy level E1 while emit a photon. Beam amplification by stimulated emission of radiation from the foregoing, stimulated emission and absorption at the same time exist in the optical radiation and particle system is in the same overall among the two opposing aspects, the possibility of their occurrence is the same, these two aspects Stimulated emission and absorption which is a dominant, depending on the particle issued in two energy distribution of laser laser is the use of stimulated radiation. The harmonious production environment of  green laser pointer  is necessary.