BBO(β相偏硼酸钡晶体)

 

BBO晶体是一种新型的紫外倍频晶体,具有较大的相位匹配范围以及较宽的透过波段,其倍频转换效率比较高,并具有很高的激光损伤阈值。应用:激光倍频、光参量放大、电光调Q等。由于BBO具有较低的潮解性,我们使用了一种有效的保护镀膜(P-coating)来防止晶体受潮。

Advantages of BBO Crystals

  • Broad phase-matching range from 409.6 nm to 3500 nm
  • Wide optical transmission from 190 nm to 3500 nm
  • Large effective second-harmonic-generation (SHG) coefficient
  • High damage threshold of 10 GW/cm2 for 100 ps pulse-width at 1064 nm
  • Wide temperature-bandwidth of about 55℃
  • 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 c, , , , , rystals , , , , , , , 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°
AR/AR@1064&532nm
BBO002
4x4x7
I
47.6°
AR/AR@532&266nm
BBO003
4x4x10
I
22.8°
AR/AR@1064&532nm
BBO004
4x4x10
I
47.6°
AR/AR@532&266nm
BBO005
5x5x2
I
29.2°
AR/AR@800&400nm
BBO006
5x5x1
I
29.2°
AR/AR@800&400nm
BBO007
5x5x0.3-0.5
I
29.2°
AR/AR@800&400nm
BBO008
5x5x0.1
I
29.2°
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
Tan , < 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.


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