The quality of laser pointer should be recognized carefully

The quality of laser pointer should be recognized carefully.
It's brightness of the sun's 10 billion times. Its principle as early as 1916, has been found that the famous American physicist Albert Einstein, but until 1960 was only the first successful laser manufacturing. Laser is in a theoretical preparation and production practices in the context of the urgent need emerged, and it come out, you get extraordinary fast development, the development of not only the old laser optical science and optical technology gained a new life, and lead to the emergence of a new industry. Laser applications in medicine is divided into three categories: Laser Life Science, laser diagnostics, laser treatment, laser treatment is divided into: laser surgery, laser bio-stimulation of the weak non-surgical laser treatment and photodynamic therapy. The quality recognition of laser pointer is not easy to be finished well. 
Figure 3 shows the soft tissue of various laser wavelengths of light penetrate the length of the approximate number. Length in the near-infrared light penetration near the large, more than in the infrared domain or 3μm below 300nm UV field smaller. Different types of tissue, the light penetration length of the wavelength dependence of the change. Its advantages are: local vasodilation, changes in blood circulation, improve tissue hypoxia and reduce chronic inflammation promote inflammation improved absorption. The advantage of laser organisms: people living in the light of the electromagnetic field, except in special circumstances the harmful effects of light on the little organisms; the use of laser propagation in the atmosphere line features non-contact manner can be applied to organisms, but also the use of fiber-optic laser into the organism's deep. The quality recognition of laser pointer is the critical step. 
Figure 17 shows the laser confocal microscope (laser confocal microscope) schematic. From the point light sources (laser) light emitted through the condenser lens after exposure to the observation point within the sample, this time in the sample to form spots of light irradiation, the use of spatial filter lens through these spots on the detector image . Transmission-type model described above with its principles, but in fact shown in Figure 18 uses the reflection-type structure. Figure 19 shows the near-field optical microscope diagram microscope with the usual. Both the basic structure is similar, but the near-field optical microscope in existence at the close from the surface of the sample probe, the probe plays a key role to achieve super-resolution. Solid-state laser crystals used in the type of work and non-crystalline material can be divided into fluoride, salts and oxides of three categories.