The voltage needed to soak g ear Sri Lanka box only 1/10-1/5 of the Kerr cell, it is a Q-switched pulse lasers use an active device. Generally used in a pulsed solid-state lasers electro-optical Q-switched device is frequently used in the structure shown in Figure 2.6: 2,3,4 of three parts consisting of electro-optic Q-switched device is located between the material and the total reflection mirror, caught in the two the middle of the polarizer is the Pockels electro-optic box. Figure 2.6 in the solid-state lasers the Pockels Box Q-device schematic. In this structure, the Pockels box can be used either as pressurized Q-switched, when the polarizer to remove the dotted frame can also be Q for the retirement of compression. green laser pointercan also help stargazers find the targeted star that you want to observe.
Pockels box divided into two categories: one is to increase the longitudinal field, such Pockels box Q switch in the applied electric field and the incident beam in the same direction, parallel to the optical axis of the crystal; the other is to increase transverse electric field in this structure, the electric field perpendicular to the direction of propagation of the beam half-wave voltage depends on the thickness and length of the crystal, in this way has an advantage, choose the appropriate size of the crystal geometry, you can make the applied voltage significantly lower than the longitudinal plus the voltage of electricity. A structure mainly KD * P crystals; application of the latter structure of LN crystals. To Pockels box for the retire pressure tune Q. with a polarizer the KD * P electro-optic Q-switched, for example instructions. green laser pointer are the pilotages of the expansive outer space.
KD * P electro-optic Q-switched with a polarizer, enabled earlier, the wider application of electro-optic crystal Q-switched device, which is characterized by the use of the polarizer and seizure of a polarization device doubles as a partial polarizer can be calcite Grand - Friedel prism can also be used dielectric film polarizers. The device shown in Figure 2.7. KD * P, easily deliquescence, they need the use of a resealable box, usually vertical pressure. KD * P electro-optic Q-switched with a polarizer works as follows: Figure 2.7 Q-switched laser schematic with a polarizer. Of YAG rod in the excitation of the xenon lamp to produce irregular optical radiation, linearly polarized light through the polarizer, from the partial direction of the KD * P crystals, crystal axes x or y direction, and KD * P imposed by an external electric field. This kind of green laser pointer is the smallest green light pen.
The role of the applied electric field, the direction of the spindle, respectively, into the x 'and y', and the incident polarization direction at 45 °. Then the Q-switch crystal from the wave plate, so that the phase difference will be generated by linearly polarized light through the crystal, while the round trip total phase difference is linearly polarized light by this time, and from the plane of polarization rotated 90 °, In this case, by the medium polarization and KD * P modulator crystal electro-optic switch is turned off, so the cavity Q value is low, can not form the laser oscillation. At this time the entire device in the state of the low Q value, but because of the xenon lamp has been in the YAG rod pumped Metastable particle number of the working substance will be enough accumulation. This kind of green laser pointer can be used as a pointer or teaching pointer or an assistant to observe the stars.
When maximum inversion, suddenly remove the voltage of the modulated crystal wavelength optical switch quickly open, free to spread along the cavity axis of the laser by modulating the crystal, its polarization state does not occur any change in this when the cavity is in the state of the high Q value, the formation of the avalanche laser. The Pockels box for pressurized tune Q. Figure 2.6 and its working principle in nature and pressure application of withdrawal the same, but need to add a polarizer (2) and its polarizer (4 ) was the quadrature placed. In this way, if you did not give Pockels box plus voltage, the beam can not pass, the largest cavity loss, the Q value is very small. This kind ofgreen laser pointershall send stable green ray laser beam only after adjusting by human beings.
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