The wavelength of light emitted from the green pen is 532nm, the laser type is Class IIIA, uses two AAA batteries. Brightness green pen is more objective, so the eye is relatively high risk, the higher the power, the more dangerous. Generally, 5mw is commonly used in the US market allows 30mW Green Laser Pointer over 5mw in need through a special approval. There is no strict restrictions in the country, which we are asked to pay special attention to user safety, not in front of the eye or other vulnerable area, but also to prevent the laser through reflection into the eyes. Generally green with adjustable focal length will double protection switch.
For astronomers, it should choose how much power and how much the price of the means to meet the star pen refers to star demands? Personally I think 20mW to 50mW of power are more appropriate, 50mW or more of power in dim indoor conditions have to feel especially glaring. The price of the main 20mW Green laser with its bandwidth and stability related, the narrower the bandwidth, the more expensive price, but the human eye can not distinguish this point gap to the bandwidth, therefore, more economically strapped friends choose power 50mW or less, the price 100 yuan laser pointer is more appropriate. In addition, the laser pointer consumption generally larger, the principle of environmental protection and savings, with a pair of good rechargeable battery is also very necessary. Currently 50mW power price is not expensive, only a little more than 100.
In addition, many people may encounter such a problem: during the day used properly refers to star pen, how the evening on the "dead" out? It refers to the star pen used to produce medium is a semiconductor laser, various properties of semiconductors are very sensitive to temperature, at lower temperatures, the laser pointer can not work, then just hand over the 100mw laser pointer for a moment, let the temperature rises above 20 degrees, the pen will work correctly, if it is not, it should perhaps be to replace the battery.
In addition, many people may encounter such a problem: during the day used properly refers to star pen, how the evening on the "dead" out? Refers to the green laser 300mw generation principle is used: the use of a semiconductor laser is 808nm pump laser crystal, and then through the multiplier obtained. The various characteristics of the semiconductor pump laser is very sensitive to temperature, and at lower temperatures, the wavelength drift, and so can not be absorbed pump light laser medium, and therefore can not produce green light, the laser pointer can not be normal work, then just hand over the laser pointer for a moment, let the temperature rises above 20 degrees, the pen will work correctly, if it is not, it should perhaps be to replace the battery.
Green Laser Pointer Selection
1, in a dark place careful observation spot, if there is a clear description of the pan around the laser spot light lens failed.
2, whether it is a perfect spot to observe is the heart dots: within 2m of.
3, observe the brightness of the laser emitted just when the dark to light whether, and if so explain laser simson pen circuit or LD problem.