Different principles of laser pointer color categories
There are many kinds of laser Pointers, according to their color can be divided into green, red, blue and blue-purple. Currently, green is the most widely used color laser pointer for these four colors. Depending on the power, it can be as small as 5MW to 5000MW. Depending on the function, there are laser flashlights and adjustable focal length to light cigarettes. It is understood that the green light is more suitable for outdoor use and the red light is more used as an indication. There is no real difference except the color. Laser Pointers are divided into red laser Pointers, green Laser pointer, yellow laser Pointers, blue laser Pointers and purple laser Pointers according to the light source. The red laser pointer has the simplest structure. It's simple because the red laser pointer is basically just a diode powered by a battery. Laser diodes can produce this wavelength. Red laser Pointers first appeared in the 1980s. It was big and heavy and worth hundreds of dollars; It's very small and very cheap. The green laser pointer is a solid-state laser that excites the nonlinear crystal with a wavelength of 808nm to produce 1064nm infrared light, and then multiplizes the frequency to produce 532nm green light. Some green lasers operate in pulsed or quasi-continuous mode to reduce cooling problems and extend battery life. Published green lasers do not need frequency doubling and have higher efficiency. Even low-power green light can be seen at night due to Rayleigh scattering of atmospheric molecules. The laser designator is often used by astronomy enthusiasts to point at stars and constellations.
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Green laser Pointers can have a variety of power outputs. 5mW is safest and can be seen in darker light, so no more power is needed to point at the target. A yellow laser pointer with a wavelength of 593.5nm has emerged in the yellow laser pointer market. Based on DPSS technology, two laser beams with wavelength of 1064nm and 1342nm were added through nonlinear crystal. Due to the complexity of the process, the yellow laser pointer is unstable and inefficient. The output power varies with temperature from 1-10MW. If it is too hot or too cold, there will be a mode jump. This is because the size of the laser pointer does not provide the required temperature stabilization and cooling components. In addition, most 593.5nm laser Pointers operate in pulse mode to use the smaller size and power of the pumped diode. The blue laser pointer initially had only the 473nm blue laser produced by DPSS, which was low power and unstable. As Casio developed a high brightness projector with a blue laser diode (445nm), blue semiconductor diodes with a power of more than 1000mW(class 4) began mass production and popularity. The purple laser pen uses a 405nm blue-purple laser diode, which is a semiconductor laser. It is close to the ULTRAVIOLET band, with low visibility, but can stimulate fluorescence, and has the function of currency detection and chemical detection.
2021-09-18 06:13:25
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