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Analysis Of Q-switching Technology Of Laser Marking Machine

Sep 18, 2018

The laser marking machine system can be divided into two types: continuous laser and pulse laser. Compared with laser marking machine of the continuous laser, pulse laser type laser marking machine has lower threshold condition and input pump energy. In certain cases, pulsed lasers can output higher pulse energies. If a pulsed excitation is used with a larger pump energy than the original, the laser will output a higher peak, so that the laser component core component laser is a superpulse laser.

A laser marking machine using ultra-pulse technology can obtain a relatively narrow pulse width of relatively high power without increasing the cost, but laser marking must be used to obtain very high peak power or very narrow pulse width. Machine laser Q-switching technology. Q-switching technology refers to the use of a method to change the loss factor in the cavity according to a prescribed procedure. At the beginning of the pump, the optical cavity has a high loss factor, and the threshold for generating the laser is increased. The laser oscillation is generated, so that the number of particles on the metastable state can be accumulated to the level, and then the intracavity loss is suddenly lowered at the appropriate time, and the threshold is also decreased. When the number of inverted particles greatly exceeds the threshold, the stimulated radiation Increased quickly. Thus, in a very short period of time, the energy of the particles stored in the upper level converts the laser energy to form a strong laser giant pulse output.

The ultra-pulse laser marking machine has the characteristics of narrow pulse width and high peak power. The advantages are applied to materials with high threshold requirements and low thermal diffusion requirements, such as glass, leather, and ceramics. The thermal processing used in laser marking machines refers to the process of causing rapid heating when the laser beam is irradiated onto the surface of the object, and the heat changes the characteristics of the object or melts and evaporates the material. During laser marking machine processing, the laser energy acting on the material must be greater than the energy required to destroy the material, which is greater than the damage threshold of the material.

Due to the high damage threshold of glass, leather, ceramics, etc., and for glass, the energy converted into heat absorption is unevenly transmitted in the glass, which will generate thermal stress and cause the glass to burst. For leather, the energy of heat conduction The edge of the leather is burned. For ceramics, the outermost layer of ceramic is a layer of enamel, which is equivalent to glass. Therefore, these materials must use a laser marking machine with an ultra-pulse working mode.

When the laser beam of the laser marking machine is projected onto the material table, part of the energy is reflected, partially absorbed, and partially transmitted, depending on the type of material and the wavelength of the laser marking machine. Of the light energy reaching the surface of the material, the portion of the energy absorbed by the material is useful for material processing. Light energy is absorbed by the vibrational excitation of electrons and atoms, and is converted into heat energy and diffused to adjacent atoms. As the laser marking machine operates, more and more photons are absorbed, and the temperature of the material is continuously increased, thereby increasing the absorption of light energy. proportion.