A Passive Q-switch is a gadget that can accomplish Q-switching by capitalizing on the reality that the passage of optical material depends on the laser intensity at a particular wavelength. The laser freeze linker generally produces saturated absorbent crystals in passive Q-switch crystals. The absorption coefficient of saturated absorption crystal decreases with the increase of incident light strength. When the saturation value is gotten to, the loss in the laser cavity is regulated, as well as the pulse is sent out.
Some passive Q-switch crystals at here:
1. Co: Spinel passive Q-switch crystals
Co: Spinel crystal, named cobalt spinel, is a recently developed product. It is sending out a wavelength variety is 1.2-1.6 μm, which has actually been confirmed to be a really efficient passive Q-switched switch. It is extensively used in the eye-safe Er: glass laser (1.54 µm) as well as has been verified in lasers with wavelengths of 1.44 µm and also 1.34 µm.
Co: Mgal2o4( Co: spinel) has a high absorption cross-section, enabling Q switching of Er: glass lasers (flash as well as diode laser pumps) without dental caries focusing. The negligible excited state absorption results in a high comparison ratio of the Q switch. That is, the ratio of the initial to saturated taken-in signal is greater than 10.
The primary features:
- 1.3 to 1.6 mu m within the range of the low optical loss
- High damages limit
Main applications:
- Passive q-switched @ 1.54 microns
2. V: YAG passive Q-switch crystals
V: YAG crystal, the Chinese name vanadium-doped yttrium aluminum garnet, is a reasonably new crystalline material. Appropriate for 1.06 ~ 1.44 μm laser emission, specifically for 1.3 μm Nd laser. The absorption height cross-section of the ecstatic state does not appear near the absorption peak of 1300 nm.
This product has outstanding optical, mechanical, and thermal residential or commercial properties. It can be produced by the Czochralski technique. V: YAG crystals can be used in Nd: YAG, Nd: YAP, Nd: KGW, Nd: YVO 4, and various other active media to obtain the passive Q-switched laser with small structure as well as outstanding performance.
Main qualities:
- High-ground state absorption
- Not noticeable thrilled state absorption
- Q switch high contrast
- Great optical residential or commercial properties, mechanical residential or commercial properties, and thermal residential properties
- Ultraviolet-resistant high damages limit
Main application:
- Made use of laser rangefinder, laser radar as well as the passive adjusting Q laser LIBS system
3. Cr: YAG passive Q-switch crystals
Cr4+: YAG crystal, Chinese name chromium doped yttrium aluminum garnet, is an excellent product for Q switching of laser (Nd: YAG and also various other doping Nd or Yb) with wavelengths from 0.8 to 1,2 μm. A remarkable attribute of Cr4+: YAG is its high damage limit of 500-1000 MW/cm2. Its absorption band expands from 800 nm to 1200 nm as well as reaches its optimal at regarding 1060nm, with a huge cross-sectional location of absorption optimal.
Highlight:
- 500-1000 MW/cm2 high damage limit
- Highly stable chemical as well as reliability
- Good thermal conductivity, long life span
- Small passive Q-switch
- Very easy to run
Main application:
- Utilized for laser range finder, LIDAR, and LIBS passive adjusting Q laser system
- Require a short pulse laser system.
4. Cr: YSO passive Q-switch crystals
In 1991, it was uncovered that Cr: YSO( pure tetravalent chromium series) solid-state saturable absorbent could be made use of for laser applications.
In 1993, Chen et al. utilized Cr: YSO solid-state saturable absorber to efficiently act on a 694.5 nm ruby laser,
The crystal’s wide-band absorption spectrum (coming to a head at 390 nm, 595 nm, 695 nm, and 750 nm) expands from the visible area to the near-infrared region, making it a good switch for lots of lasers.
5. Cr: GSGG passive Q-switch crystals
Cr4+: GSGG can be utilized as a passive Q-switch in the 1.06 μm band. Compared with the typical Cr4+: YAG passive Q-switched crystal, Cr4+: GSGG crystal has the adhering advantages:
The visible component is clear (calibration) and also is extra useful to the laser light path, In the 1.06 mu m band has a higher absorption coefficient. At the same time, it also has a solid capacity for anti-irradiation.
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