Hello everyone:
1, laser working medium, the working medium of optical fiber laser marking machine for optical fiber.
The generation of laser must select the appropriate working medium, can be gas, liquid, solid or semiconductors.Can realize the population inversion in the medium, to create the necessary conditions for laser.Obviously the existence of meta-stable energy level, very beneficial to achieving particle count the reincarnation.The existing nearly one thousand kinds of working medium, can produce far infrared laser wavelength ranging from vacuum ultraviolet way, a very wide range.




2, excitation source


In order to make the population inversion appear in the working medium, have to use some methods to motivate the atomic system, increase the number of particles in the upper level.Usually can use the way to utilization of gas discharge has kinetic energy of the electron atoms, to inspire media called the electric excitation;Pulse light source can be used to illuminate working medium, called the optical excitation;And thermal, chemical, incentives, etc.A variety of incentives is referred to as the pump or pump visually.In order to get the laser output unceasingly, must constantly "pump" to maintain the number of particles in the upper level is more than the next level.


3, cavity resonator (CO2 laser marking machine is divided into two)


After working with the right material and excitation source, which can realize population inversion, but that the stimulated radiation strength is very weak, unable to practical application.The people then think about the amplification using optical resonator.The so-called optical cavity, actual it is on both ends of the laser, use two pieces of high reflectivity mirror face to face.A piece of almost total reflection, a everbright reflection, a small amount of transmission parts, so that the laser can penetrate through the mirror.Be reflected back to the light of the working medium, continue to induce new stimulated radiation, light to be amplified.Therefore, light oscillates back and forth in the cavity, causing a chain reaction, an avalanche gain amplifier, produce intense laser, from one end part of the reflection mirror output.Ruby laser as an example to illustrate the formation of the laser.Working substance is a ruby bar.Ruby is mixed with a little 3 3 oxidation 2 aluminium chromium ions in crystals.Actual it is mixed with mass ratio is about 0.05% of the chromic oxide.Because of the chromium ion absorption of white light green and blue, so the pink stones.1960 maiman with ruby from the invention of the laser is a 0.8 cm in diameter, about 8 cm long, round bar.Two end face is a pair of parallel plane mirror, total reflection on the side plating membrane, 10% transmittance at one end, can let a laser passes.Ruby laser, with high-pressure xenon lamp as a "pump", the use of xenon lamp light emitted from inspire chromium ion to excited state E3, is pumped to the electrons in the E3 soon (8 ~ 10 - s) by the radiative transition to E2,the laser marking machine price is reasonable.




E2 is metastable level E2 to E1 spontaneous emission probability is small, life is up to 10-3 s, allowing the particles to stay a long time.So the particles accumulate on E2, realization of E1 and E2 on two level of population inversion.From E2 to the E1 stimulated emission of radiation red laser wavelength is 694.3 nm.By pulse xenon lamp is pulsed laser, each of the light pulse duration less than 1 ms, each optical pulse energy in more than 10 j;In other words, each of the pulse laser power can be orders of magnitude more than 10 kw.Notice of the chromium ion from excitation to lase process involves three levels, the so called three level system.Because in a three level system, E1 level is under the ground state, usually accumulate a large number of atoms, so to achieve population inversion, have to have quite a strong incentive,the prospect of laser marking machine for saleis very good.


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