Products >> Optical Crystals >> Laser Crystals >> KGW & Ba(NO₃)₂

KGW & Ba(NO₃)₂

ILOPTIK supplies two crystal materials: Barium Nitrate (Ba(NO₃)₂) and undoped Potassium Gadolinium Tungstate (KGd(WO₄)₂, abbreviated as KGW). Both materials exhibit outstanding performance in Stimulated Raman Scattering (SRS) and are widely applied for laser frequency conversion to broaden the wavelength tuning range. The SRS technology based on these crystals is fully compatible with modern all-solid-state laser systems, offering a simple and compact solution for laser frequency conversion.

Contact Inquiry

Technical Specifications

Custom specifications available upon request

Barium Nitrate (Ba(NO₃)₂) possesses an extremely high Raman gain coefficient, which directly determines the threshold of Raman lasers. However, this material suffers from a severe thermal lens effect, manifested by a large thermo-optic coefficient (∂n/∂T) and low thermal conductivity. In contrast, KGW delivers much weaker thermal effects and an extremely high optical damage threshold, making it an ideal candidate for high-power laser operation.

For Raman laser applications, Ba(NO₃)₂ is more suitable for nanosecond and longer pulse lasers, while KGW shows superior performance for shorter pulse lasers.

Ba (NO₃)₂ Basic Characteristics

Physical Property	Value
Material	Ba (NO₃)₂
Transmission range	Cubic，P2₁3
Density	0.35 – 1.8 μm
Hardness Mohs	3.25 g/cm³
Refractive indices @ 1064 nm	2.5 – 3
Raman shift	n = 1.555
Raman gain, pump 1064 nm	1048 cm⁻¹
Thermal conductivity, W/mK	11 cm/GW
∂n/∂T	1.17
Optical Damage Threshold	-20×10⁻⁶ K⁻¹
Transmission range	~ 0.4 GW/cm²

KGW Basic Characteristics

Physical Property	Value
Material	KGW
Crystal symmetry	monoclinic，C2/c
Transmission range	0.35–5.5 μm
Density	7.27 g/cm³
Hardness Mohs	4 – 5
Refractive indices @ 1064 nm	ng=2.061；nm=2.010；np=1.982
Raman shift	901 cm⁻¹ (p[mm]p) 768 cm⁻¹ (p[gg]p)
Raman gain, pump 1064 nm	3.3 cm/GW (901 cm⁻¹) 4.4 cm/GW (768 cm⁻¹)
Thermal conductivity, W/mK	Ka=2.6；Kb=3.8；Kc=3.4
∂n/∂T	0.4 × 10⁻⁶ K⁻¹
Optical Damage Threshold	> 10 GW/cm²

General Crystal Specifications

Material	Ba(NO₃)₂	KGW
Surface quality, scratch & dig (MIL-PRF-13830B)	40-20	10-5
Flatness @ 633 nm	λ/4	λ/8
Max element dimensions, mm	10×10×100	10×10×80

Raman Wavelength Parameters of KGW & Ba(NO₃)₂ Crystals

Stoke	KGW 532 nm	KGW 1064 nm	Ba (NO₃)₂ 532 nm	Ba (NO₃)₂ 1064 nm	典型效率 (%)
1 Stoke	558	1177	563	1197	35–70
2 Stoke	588	1316	598	1369	20–40
3 Stoke	621	1494	638	1599	10–15
4 Stoke	658	1726	684	1924	<10
1 Antistoke	507	970	503	957	10–30