Passive Q switch crystals

A Passive Q switch is a tool that can attain Q switching by making the most of the reality that the transmittance of optical material relies on the laser intensity at a specific wavelength. The laser freeze linker mostly generates saturated absorbing crystals in passive Q-switched crystals. The absorption coefficient of saturated absorption crystal lowers with the rise of occurrence light strength. When the saturation worth is reached, the loss (Q value) in the laser dental caries is modulated, and the pulse is emitted.

Some passive Q switch crystals are listed below:

Co: Spinel crystal

Co: Spinel crystal, named cobalt spinel, is a newly created product. Its giving off wavelength array is 1.2-1.6 μm, which has actually proved to be a very effective passive Q-switched switch. It is commonly made use of in the eye-safe Er: glass laser (1.54 µm) as well as has been confirmed in lasers with wavelengths of 1.44 µm and 1.34 µm. Co: Mgal2o4( Co: spinel) has a high absorption cross-section, making it possible for Q switching of Er: glass lasers (flash as well as diode laser pumps) without cavity focusing. The minimal thrilled state absorption causes a high comparison ratio of the Q switch. That is, the ratio of the first to saturated soaked up signal is greater than 10.

The primary features of Co: Spinel crystal:

  • 1.3 to 1.6 mu m within the scope of the reduced optical loss
  • High damage threshold

Main applications of Co: Spinel crystals:

  • Passive q-switched @ 1.54 microns

V: YAG passive Q switch crystal

V: YAG crystal, the Chinese name vanadium-doped yttrium aluminium garnet, is a relatively brand-new crystalline material. Ideal for 1.06 ~ 1.44 μm laser discharge, particularly for 1.3 μm Nd laser. The absorption peak cross-section of the ecstatic state is not apparent near the absorption peak of 1300 nm. This material has outstanding optical, mechanical and thermal buildings. It can be generated by the Czochralski method. V: YAG crystals can be used in Nd: YAG, Nd: YAP, Nd: KGW, Nd: YVO 4 as well as other energetic media to acquire the passive Q-switched laser with small structure and superb efficiency.

The V: YAG crystal main characteristics:

  • High-ground state absorption
  • Not apparent ecstatic state absorption
  • Q switch high contrast
  • Excellent optical homes, mechanical residential properties and thermal homes
  • Ultraviolet immune high damages limit

V: YAG crystal main application:

  • Laser rangefinder
  • Laser radar
  • The passive adjusting Q laser LIBS system


Cr4+: YAG crystal, Chinese name chromium doped yttrium aluminium garnet, is an ideal product for Q switching of laser (Nd: YAG as well as other doping Nd or Yb) with wavelengths from 0.8 to 1,2 μm. A noteworthy feature of Cr4+: YAG is its high damages threshold of 500-1000 MW/cm2. Its absorption band expands from 800 nm to 1200 nm and reaches its top at regarding 1060nm, with a very large cross-sectional location of absorption optimal.

Cr: YAG crystal highlight:

  • 500-1000 MW/cm2 high damages threshold
  • Extremely stable chemical as well as dependability
  • Good thermal conductivity, long service life
  • Small passive Q switch
  • Easy to operate

The Cr: YAG crystal main application:

  • Utilized for laser range finder, LIDAR as well as LIBS passive adjusting Q laser system
  • Need a brief pulse laser system

Cr: YSO passive Q switch crystal

In 1991, it was discovered that Cr: YSO( pure tetravalent chromium series) solid-state saturable absorbing could be used for laser applications.

In 1993, Chen et al. made use of Cr: YSO solid-state saturable absorber to efficiently act upon a 694.5 nm ruby laser,

The crystal’s wide-band absorption spectrum (peaking at 390 nm, 595 nm, 695 nm, and also 750 nm) extends from the visible region to the near-infrared area, making it a great switch for many lasers.


Cr4+: GSGG can be utilized as a passive Q-switch in the 1.06 μm band. Compared with the conventional Cr4+: YAG passive Q-switched crystal, Cr4+: GSGG crystal has the complying with advantages:

  • In the noticeable part is clear (calibration) and also is extra useful to the laser light path
  • In 1.06 mu m band have a better absorption coefficient. At the same time, it likewise has a solid capability for anti-irradiation

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