BBO

BBO crystal is an efficient NLO crystal for the second, third and fourth harmonic generation of Nd:YAG lasers, and the best NLO crystal for the fifth harmonic generation at 213 nm. Conversion efficiencies of more than 70% for SHG, 60% for THG and 50% for 4HG, and 200 mW output at 213 nm (5HG) have been obtained, respectively. BBO crystal has the following.

Advantages of BBO Crystals

Broad phase-matchable range from 409.6 nm to 3500 nm

Wide transmission region from 190 nm to 3500 nm

Large effective second-harmonic-generation (SHG) coefficient about 6 times greater than that of KDP crystal

High damage threshold

High optical homogeneity with dn > 10^-6/cm

Wide temperature-bandwidth of about 55°C.

Good mechinical and physical properties

Capabilities:

Aperture:	2x2 ~ 25x25mm
Lenght:	0.01 - 25mm
Cutting Angle of BBO Crystals And:	Determined by different kinds of homonic generartion
Phase matching type:	Type I or Type II
End Configuration:	Plano/Plano or Brewst/Brewst or Specified

Specifications of BBO Crystals

Angle tolerance:	Δθ< ± 0.5°; Δφ< ±0.5°
Dimensional Tolerance:	(W ± 0.1mm) x (H ± 0.1mm) x (L + 0.2mm/-0.1mm)
Flatness:	<λ/8 at 633nm
Surface Quality:	10/5 S/D
Parallelism:	< 20 arc seconds
Perpendicularity:	< 5 arc minutes
Wavefront Distortion:	<λ/8 at 632.8nm
Clear Aperture:	Central 95%
Chamfer:	0.15x45^°
Coating:	* Protective coating is required to prevent polished surfaces from fogging. * Anti-reflective coating should be considered if low reflectivity is required.

Properties of BBO Crystal:

Sellmeier Equations:

no2(l) = 2.7359+0.01878/(l2-0.01822)-0.01354 l2
ne2(l) = 2.3753+0.01224/(l2-0.01667)-0.01516 l2

BBO optical properties:

Transparence range: 189-3500nm
Second harmonic generation (SHG) range: 410-2400nm
Type I phase matching plane: X-Z plane, f=0o
Type I phase matching plane: X-Z plane, f=30o

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

1) Harmonic generations of Nd:YAG lasers:

1064nm SHG --> 532nm: 4x4x7mm Type I , q=22.8??, f=0o;
1064nm THG --> 355nm: 4x4x7mm Type I, q=31.3o, f=0o; Type II q=38.6o, f=30o
1064nm 4HG --> 266nm: 4x4x7mm Type I, q=47.6o, f=0o;
1064nm 5HG --> 213nm: 4x4x7mm Type I, q=51.1o, f=0o;

2) OPO and OPA pumped by harmonics of Nd:YAG lasers

532nm Pump --> 680-2600nm: 8x6x12mm Type I, q=21o, f=0o;
355nm Pump --> 410-2600nm: 8x6x12mm Type I, q=30o, f=0o; Type II, q=37o, f=30o;
266nm Pump --> 295-2600nm: 8x6x12mm Type I, q=39o, f=0o;

3) Frequency doubling of dye lasers

670-530nm SHG --> 335-260nm: 8x4x7mm Type I, q=40o, f=0o;
600-440nm SHG --> 300-220nm: 8x4x7mm Type I, q=55o, f=0o;
444-410nm SHG --> 222-205nm: 8x4x7mm Type I, q=80o, f=0o;

4) Harmonic generations of Ti:Sapphire lasers

700-1000nm SHG --> 350-500nm: 5x5x0.2mm Type I, q=28o, f=0o;
700-1000nm THG --> 240-330nm: 5x5x0.2mm Type I, q=42o, f=0o;
700-1000nm FHG --> 210-240nm: 5x5x0.2mm Type I, q=66o, f=0o;

5) Frequency doubling and tripling of alexandrite lasers

720-800nm SHG --> 360-400nm: 6x4x7mm Type I, q=31o, f=0o;
720-800nm THG --> 240-265nm: 6x4x7mm Type I, q=48o, f=0o;

6) Intracavity SHG of Ar+ laser with brewster angle cut BBO

514nm SHG --> 257nm: 4x4x7mm Type I, q=51o, f=0o, B-cut;
488nm SHG --> 244nm: 4x4x7mm Type I, q=55o, f=0o, B-cut;

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

Part No.	Size(mm)	Type	Θ	Φ	Coating
BBO001	4x4x7	I	22.8°	0°	AR/AR@1064&532nm
BBO002	4x4x7	I	47.6°	0°	AR/AR@532&266nm
BBO003	4x4x10	I	22.8°	0°	AR/AR@1064&532nm
BBO004	4x4x10	I	47.6°	0°	AR/AR@532&266nm
BBO005	5x5x2	I	29.2°	0°	AR/AR@800&400nm
BBO006	5x5x1	I	29.2°	0°	AR/AR@800&400nm
BBO007	5x5x0.3-0.5	I	29.2°	0°	AR/AR@800&400nm
BBO008	5x5x0.1	I	29.2°	0°	AR/AR@800&400nm

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
Mohs Hardness	4.5
Density	3.85 g/cm3
Absorption Coefficient	< 0.1%/cm (at 1064 nm)
Hygroscopic Susceptibility	low
Resistivity	> 1011 ohm-cm
Relative Dielectric Constant	T11/ 0: 6.7, T33/ 0: 8.1 ,dTan < 0.001
Thermal Expansion Coefficients(in the range of 25℃- 900℃)	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	205nm-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/℃ dne/dT = -16.6 x 10-6/℃

Note: Other sizes, cut angle, coating are available upon request.