Changes in the characteristics of the laser pointer
"Classic" lasers produce ultrashort laser pulses designed to maximize the coherence of the emitted beam. In particular, it attempts to obtain "single-mode" radiation by manipulating the shape of the laser cavity. This means that we only want to allow radiation in very precise directions, lengths and very precise waves.
However, Heisenberg's uncertainty principle prohibits pulses that are too short for single-mode lasers. However, it must generate pulses of 100 fs or shorter, that is, one millionth of a second. Therefore, choose a laser pointer crow material that can emit light in a wide band (spectral width of tens of nanometers), and construct a cavity so that the laser effect can be obtained in this wavelength range, that is, in a variety of modes. All these modes need to be synchronized. Only when they are all fired at the same time, the transmitted pulse will be shortened. However, each of them is randomly synchronized based on the spontaneous emission that produced it. To solve this problem, a "saturable absorber" was added to the cavity. This is when the pattern is distributed over time and is opaque at low light intensities but passes the strongest, that is, when the pattern occurs. It happened at the same time.
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Wavelength
The stars will improve the green. The recommended 5mw green high power laser pointer is 5-10 times brighter than the 5mW red laser because the human eye sees green much better than the same amount of red or blue. Looking at the green light beams in the sky will not affect the night vision. To maintain night vision, do not look directly at the laser dots on bright surfaces or colors. This technique reversibly extends ultrashort pulses from the oscillator by their wide spectral width. Thanks to the grating, each spectral component of the pulse (each "color") is separated and traverses a path of different length, and then recombined into the same beam using a second grating. .. In this way, a pulse with a thousand times widening can be obtained, and it can pass through the amplifier without damaging the amplifier, so as to achieve the required energy of up to a few joules or more per pulse.
2021-10-27 11:54:13
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