Interesting nonlinear optical crystal
The nonlinear optical crystal is the crystal which reveals the nonlinear optical impact more than twice for the laser electric field. Nonlinear optical crystal is a kind of useful product, in which the frequency-doubling (or “regularity conversion”) crystal can be made use of to convert the laser wavelength, so as to extend the tunable range of the laser, which has crucial application worth in the field of laser technology.
Nonlinear crystal properties
For nonlinear optical crystals, in addition to having big reliable nonlinear coefficients, the complying with buildings are likewise needed:
- In general, the crystal must have high transparency for the wavelength entailed;
- the interior absorption needs to be reduced, the anti-damage limit must be high;
- Steady physical and also chemical homes, modest hardness, no deliquescence;
- Steady crystal quality, plus size, affordable price, simple covering.
There are numerous different kinds of nonlinear crystals, Common lithium niobate (LiNbO3– LN), lithium tantalate (LiTaO3– LT), potassium dihydrogen phosphate (KH2PO4– KDP), potassium dideuterium phosphate (KD2PO4– DKDP), lithium iodate (LiIO3– LI), potassium titanium phosphate (KTiOPO4– KTP), barium metaborate (BaB2O4– BBO), lithium trisborate (LiB3O5– LBO), potassium niobate (KNbO3– KN), cesium borate (CSB3O5– CBO), cesium lithium borate (LiCSB6O10– CLBO), potassium beryllium fluorborate (KBe2BO3F2– KBBF), silver thiogas (AgGaS2– AGS), silver selenium gallium (AgGaSe2– AGSe, arsenic-cadmium germanium (CDGEAS-CGA), cadmium selenide CdSe, Gallium selenide GaSe, phospho-germanium zinc (ZnGEP2-ZGP) are widely made use of in laser regularity increasing, sum frequency, distinction frequency, optical parametric amplification, electro-optic inflection, electro-optic deflection, and so on.
Below are some examples of usual nonlinear optical crystals.
BBO nonlinear crystal is recognized as one of the most exceptional second-order nonlinear optical crystal on the planet. One of its amazing characteristics is its broad regularity modulation variety. Extra notably, by utilizing its regularity down-conversion process, BBO crystal can be made into a continually tunable fully healed tuned laser with wavelength from visible to near-infrared.
Barium borate (BBO) has huge birefringence as well as reduced dispersion, high damages limit, wide phase matching range, excellent temperature level security, huge nonlinear optical effect, and the frequency doubling coefficient is 6 times that of KDP crystal. It has a very wide variety of pervious to light, reduced absorption coefficient, the weak the piezoelectric ringing result, relative to various other crystal electro-optic inflection, has greater extinction ratio, the bigger phase in a supporting duty, high optical damages limit, the temperature level of the broadband matching, as well as outstanding optical homogeneity and also to improve the laser result power stability, Particularly for the three-way regularity Nd: YAG laser has a variety of applications.
Lithium trisborate, additionally called LBO, is an outstanding high-power UV frequency-doubling crystal with vast passage band, high damages limit and also huge acceptance Angle. Lithium trisborate (LiB3O5, referred to as LBO) crystal is usually used in center and also high power 1064nm dual and also three-way regularity lasers. It has very high light damages resistance limit, excellent light harmony, wide obtaining Angle, great mechanical buildings, solid thermal shock resistance, microdelixation, and big nonlinear coefficient.
It is just one of the nonlinear crystals with outstanding detailed buildings. The biggest benefit of LBO is that it can utilize temperature tuning to achieve non-critical stage matching (NCPM). When the frequency doubling procedure pleases the non-critical phase matching relationship, the departure Angle between the basic frequency and the second harmonic of the regularity increasing is 0. Currently, the effective length of the LBO crystal can theoretically get to infinity, which can make up for its small nonlinear coefficient. Due to its big damage limit, this suggests that high-power fundamental wave pumping can be accomplished.
Compared to LiNbO3 crystal, MgO: LiNbO3 crystal has its special benefits in the application of NCPM regularity increasing, blending and optical parametric oscillation in ND-doped lasers.
The anti-damage threshold of drugged MgO: LiNbO3 crystal is more than twice higher than that of pure LiNbO3 crystal.
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