The brightest laser pointer in the night sky

Laser flashlight is a rookie in astronomy, must be experienced and worth collecting. Don’t feel expensive, let’s take a look at the shocking beam of light, the range of more than two kilometers, the battery life of more than 5 hours, the good temperature control, and the appearance and value, let’s take a look at the effect first. The excitation source of the star pen is mostly a krypton arc lamp, an iodine tungsten lamp or a potassium rubidium lamp; the solid working medium is a nonlinear crystal.Doping the metal ion with "stimulated emission" effect into the crystal can convert the light energy generated by the excitation source into a near-infrared laser of about 1000 nanometers, and then convert the frequency double into 532 nanometers, in this way, the emitted laser light becomes green.Direct use of laser pen instead of star finder mirror, laser pen and telescope calibration can be directly aimed at the target, the advantage is simple and intuitive, the disadvantage is also unable to aim at the dark target, easy to interfere with other astronomical observers (especially photography) you laser, may be more than ten minutes of exposure of the film will be wasted. And lasers can be dangerous.