BBO Crystal, BBO Crystal, BBO Crystal, Beta Barium Borate

BBO or beta-BaB₂O₄ is a nonlinear optical crystal which combines a number of unique features.  These features include wide transparency and phase matching ranges, large nonlinear coefficient, high damage threshold and excellent optical homogeneity.  Therefore,  BBO provides an attractive solutions for various nonlinear optical applications.

Availability:

Typical Specification and Tolerance:

Notes:
To inquiry or order a finished BBO crystals, please provide specifications as listed in the above.  For nonlinear crystals, the maximum conversion efficiency is mainly determined by three specification: crystals length, phase matching type, and phase matching angles(θand φ).

Please refer to "How to order a nonlinear crystal" for details.

Physical and Optical Properties:
 

Crystal Structure	trigonal, space group R3c
Cell Parameters	a = b = 12.532Ä, c = 12.717Ä, Z = 6
Melting Point	1095 +/-5°C
Transition Temperature	925 +/-5°C
Optical Homogeneity	Dn ≈10-6/cm
Hardness	4.5 Mohs
Density	3.85 g/cm3
Absorption Coefficient	< 0.1%/cm (at 1064 nm)
Hygroscopic Susceptibility	low
Resistivity	> 1011 ohm-cm
Relative Dielectric Constant	eT11/e0: 6.7, eT33/e0: 8.1 Tan d, < 0.001
Thermal Expansion Coefficients(in the range of 25°C- 900°C)	a, 4 x 10-6/K c, 36 x 10-6/K
Thermal Conductivity	^c, 1.2 W/m/K; ||c, 1.6 W/m/K

 

Phase-matchable SHG range	189-1750nm
NLO coefficients	d11 = 5.8 x d36(KDP) d11 = 0.05 x d11, d22< 0.05 x d11
Electro-Optic Coefficients	g11 = 2.7 pm/V, g22, g31< 0.1 g11
Half-Wave Voltage	48 KV (at 1064 nm)
Damage Threshold at 1.064 mm at 0.532 mm	5 GW/cm2 (10 ns); 10 GW/cm2 (1.3 ns)1 GW/cm2 (10 ns); 7 GW/cm2 (250 ps)
Transparency Range	189 - 3500 nm
Refractive Indices at 1.0642 mm at 0.5321 mm at 0.2660 mm	ne = 1.5425, no = 1.6551 ne = 1.5555, no = 1.6749 ne = 1.6146, no = 1.7571
Therm-Optic Coefficients	dno/dT = - 9.3 x 10-6/°C dne/dT = -16.6 x 10-6/°C
Sellmeier Equations:	no2(l) = 2.7359+0.01878/(l2-0.01822)-0.01354 l 2 ne2(l) = 2.3753+0.01224/(l2-0.01667)-0.01516 l 2

As a result of large thermal acceptance bandwidth, high damage threshold and small absorption BBO well suits for frequency conversion of high peak or average power laser radiation.The large spectral transmission range as well as phase matchability, especially in UV range, makes BBO perfectly suitable for frequency doubling of Dye, Ar+-ion and Copper vapour laser radiation, effective cascade harmonic generation of wide spread Nd:YAG as well as of Ti:Sapphire and Alexandrite laser radiation.  Both angle tuned Type 1 (oo-e) and Type 2 (eo-e) of phase matching can be obtained increasing a number of advantages for different applications.  SHG phase matching angle dependence on input radiation wavelength is shown in fig. 2

Both Type 1 and Type 2 phase matching are used in OPO devices based on BBO crystals and designed for pump at different harmonics (up to fifth) of Nd:YAG lasers. Type 1 of interaction gives a larger tuning range and higher parametric amplification rate comparing to type 2 of interaction, while using type 2 interaction you are obtaining narrower bandwidth of output. Parametric gain in BBO is about 10 times higher then in KDP in case of 355 nm pump for type 1 interaction. Up to 30% energy conversion efficiency has been obtained using BBO crystal of 12 mm length in OPO device synchronously pumped at 532 nm, which outputs at 406-3170 nm. Because of small acceptance angle and large walk off, the use of input laser radiation with good beam quality and low divergence is required for efficient conversion.

The crystals with different angle cut for various applications are listed as follows:

1) Harmonic generations of Nd:YAG lasers:
1064nm SHG --> 532nm: Type I , q=22.8°, f=0°;
1064nm THG --> 355nm: Type I, q=31.3°, f=0°; Type II q=38.6°, f=30°
1064nm 4HG --> 266nm: Type I, q=47.6°, f=0°;
1064nm 5HG --> 213nm: Type I, q=51.1°, f=0°;

2) OPO and OPA pumped by harmonics of Nd:YAG lasers
532nm Pump --> 680-2600nm: Type I, q=21°, f=0°;
355nm Pump --> 410-2600nm: Type I, q=30°, f=0°; Type II, q=37°,  f=30°;
266nm Pump --> 295-2600nm: Type I, q=39°, f=0°;

3) Frequency doubling of dye lasers
670-530nm SHG --> 335-260nm: Type I, q=40°, f=0°;
600-440nm SHG --> 300-220nm: Type I, q=55°, f=0°;
444-410nm SHG --> 222-205nm: Type I, q=80°, f=0°;

4) Harmonic generations of Ti:Sapphire lasers
700-1000nm SHG --> 350-500nm: Type I, q=28°, f=0°;
700-1000nm THG --> 240-330nm: Type I, q=42°, f=0°;
700-1000nm FHG --> 210-240nm: Type I, q=66°, f=0°;

5) Frequency doubling and tripling of alexandrite lasers
720-800nm SHG --> 360-400nm: Type I, q=31°, f=0°;
720-800nm THG --> 240-265nm: Type I, q=48°, f=0°;

6) Intracavity SHG of Ar+ laser with brewster angle cut BBO
514nm SHG --> 257nm: Type I, q=51°, f=0°, B-cut;
488nm SHG --> 244nm: Type I, q=55°, f=0°, B-cut;

Mounting:

In order to prevent crystals from damaging or to be easily operated, we provide three kinds of mount of holder to install different dimension crystals. Please contact our sales for more information.