And the indication light of laser pointer is red

And the indication light of  laser pointer is red
Therefore, a large number of particles at the same excitation of the coherent radiation field generated by stimulated emission of light is coherent. Monochromatic energy density by the stimulated emission transition probability and the stimulated absorption transition probabilities are proportional to the incident radiation field. When two levels of statistical weight equal to the probability of the two processes are equal. N2, <N1 in the case of thermal equilibrium, so spontaneous absorption transition dominated by the light through the material, usually due to shock absorption and attenuation. External energy incentives can destroy heat balance N2, leaving> N1, this state is called population inversion state. In this case, the stimulated emission transition dominant. As long as there are no metal shielding obstacles between the emitter and receiver of RF remote control  laser pointer . 
Aluminum surface had been FeNiCr alloying process and found that the aluminum alloy surface hardening phase, Al9NiFe and electric locomotive technology A1FeNiSi strengthen the aluminum surface. Laser surface alloying than his competitors - the ordinary arc surface hardening and plasma spraying some superiority. Arc surface hardening and plasma spraying, the radiation energy-dispersive and therefore can not through the air to distant spread of the highly centralized type of laser they heat distribution dispersed much more. Their power density close to the level of the laser. Beijing Machine Tool Research Institute Zhangkui Wu et al, centerless grinding machine pallets 45 steel processing with laser alloying of composite alloy powder used in the production workshop. This kind of laser pointer has the special star effect.
3 to 4 times than the original CrWMn steel quenching pallet life. Chongqing University, Beijing University and other units using laser surface alloying process, the punch pins for electrical processing of seamless steel pipe perforation head and slurry pump impeller and other parts, we have achieved very good results. Beijing Institute of Electrical and Mechanical Services told the tractor to change to the the forehearth fork, nut tapping machine, bearing a reaming mode, red wood mold, applied research, on the power plant row of pink blades, and aluminum pistons and other parts have achieved good effect. Fork, forehearth life of more than 10 times. Red wood mold, a row of pink blades service life by 2 to 3 times.