|   

Your present location:HomeproductsProductNLO Crystal > BiBO
  • Name: BiBO
  • No.: 114
  • Update: 2014-06-09
  • Views : 496

Bismuth Borate (BiB3O6 or BIBO) crystal is a nonlinear optical crystal with large effective nonlinear coefficient (about 9 times higher than KDP, 3.5-4 times LBO, 1.5-2 times BBO and 1.2 times KTP, respectively), high damage threshold and non-hydroscopic. 

With an outstanding ability for generation of SHG and THG of Nd- lasers (1342nm, 1319nm, 1064nm, 946nm and 914nm), BIBO is an excellent non-linear optical crystal to get red, green, and blue laser beams.

APPLICATION:

BIBO crystals are mainly employed in following applications:

SHG and THG for middle and high power Nd: lasers at 1064nm

SHG and THG of high power Nd-lasers at 1342nm and 1319nm for red and blue lasers

SHG for the Nd- Lasers at 914nm and 946nm for blue laser

Optical Parametric Amplifiers (OPA) and Oscillators (OPO) application

 

Some typical experiment results are listed as follows for reference:

 

ØBy introducing frequency doubling to a diode-pumped Nd:YAG laser with BIBO crystal, a continuous-wave (CW) blue radiation of up to 2.86 W at 473nm was realized. A comparison of SHG@ 946nm is listed in the following table:

 

Crystals

Length

Deff

Walk-off

Output Power(W)

Convertion

efficiency

(mm)

(pm/V)

(mrad)

BIBO

10.4

3.3

40.7

2.8

63%

LBO

10

0.81

11.3

1.52

33%

BBO

8

2

60.3

2.1

47%

 

Researchers at Universität Hamburg in Germany have set a record for blue CW power generated from a diode-pumped solid-state laser using BiBO, to frequency-double the 946-nm line of the Nd:YAG. The intracavity frequency-doubled laser produced up to 2.8 W of 473-nm light when it was pumped with 21 W of 808-nm radiation from a diode laser, an approach that may lead to more efficient, less expensive blue lasers in the commercial market. 
The 946-nm laser's mirrors had low reflectivity at 1064 nm to suppress the Nd:YAG's stronger line at that wavelength. The 946-nm transition terminates on the upper Stark-split branch of the ground state, which is approximately 0.7 percent populated at room temperature. This quasi-three-level behavior causes laser photons to be reabsorbed by the ground level in the unpumped regions of the laser rod. To prevent this reabsorption, the researchers matched the longitudinal pump beam very closely to the intracavity laser mode. 
The laser produced 4.6 W of 946-nm radiation in the initial configuration (a). With an intracavity frequency-doubling crystal of LBO, BBO or BiBO (b), the setup yielded 1.5, 2.1 or 2.8 W of 473-nm light, respectively.    Type I phase-matching in nonlinear crystal requires
 that the laser be linearly polarized. But because thermal gradients in the laser rod are circularly symmetric, the rod's thermal birefringence is in polar coordinates. That is, the fast and slow axes have different orientations at different locations across the rod's cross section, so linearly polarized light passing through the rod becomes depolarized. This intracavity depolarization loss can seriously diminish the output power. 
   Other researchers had shown that placing a quarter-wave plate between the laser rod and the back mirror will cause the worst parts of the depolarization to be reversed on a second passage through the rod. The Hamburg group borrowed this simple trick to boost its laser's output by more than 25 percent. 
   In the arrangement used in the experiment, the laser produced 4.6 W of polarized 946-nm output in the configuration that included a 3.3 percent output coupler for that wavelength. When the output mirror was replaced with a high-reflection mirror for both the IR and blue wavelengths and a BiBO crystal was placed in the resonator, blue output of 2.8 W was obtained through the second curved folding mirror, which was highly transmissive at 473 nm. 
   The group also experimented with two better-known nonlinear crystals in this second configuration. A 10-mm-long LBO crystal produced 1.5 W, and an 8-mm-long BBO crystal produced 2.1 W. The 10.4-mm-long BiBO crystal produced 2.8W.

  
                                          
 ADVANTAGE:

broad transparent range from 286nm to 2500nm;

large effective nonlinear coefficient;

high damage threshold;

Wide temperature bandwidth

Non hygroscopic

 

 

 

Dimension Tolerance

W(+/-0.1)*H(+/-0.1)*L(+0.5/-0.1)mm

Angle Tolerance

+/-0.25°

Perpendicularity

≤10′

Scratch/Dig

20/10

Chamfer

≤0.2mmx45°

Parallelism

10″

Chips

≤0.1mm

Flatness

λ/10@633nm

Clear Aperture

≥90%

Wavefront distortion

λ/8@633nm

Coatings

C1---AR@1342(<0.2%)&671(R<0.5%)nm

C2---AR@1319(<0.2%)&659.5(R<0.5%)nm

C3---AR@1064(<0.2%)&532(R<0.5%)nm

C4---AR@946(R<0.2%)&473(R<0.5%)nm

C5---AR@914(R<0.2%)&457(R<0.5%)nm

C6---AR@800(R<0.2%)&400(R<0.5%)nm

Damage Threshold

500MW/cm² (1064nm, 10ns, 10Hz)

 

 

 

P/N

Cut  Angle

Size(mm)

Coating

Application

BIBO-335-C1/C1

Θ=8.8°φ=0°

3x3x5

AR/AR@1342&671nm

Type I SHG@1342nm

BIBO-3310-C1/C1

Θ=8.8°φ=0°

3x3x10

AR/AR@1342&671nm

Type I SHG@1342nm

BIBO-335-C2/C2

Θ=8.3°φ=0°

3x3x5

AR/AR@1319&659.5nm

Type I SHG@1319nm

BIBO-3310-C2/C2

Θ=8.3°φ=0°

3x3x10

AR/AR@1319&659.5nm

Type I SHG@1319nm

BIBO-335-C3/C3

Θ=168.7°φ=90°

3x3x5

AR/AR@1064&532nm

Type I SHG@1064nm

BIBO-3310-C3/C3

Θ=168.7°φ=90°

3x3x10

AR/AR@1064&532nm

Type I SHG@1064nm

BIBO-335-C4/C4

Θ=161.6°φ=90°

3x3x5

AR/AR@946&473nm

Type I SHG@946nm

BIBO-3310-C4/C4

Θ=161.6°φ=90°

3x3x10

AR/AR@946&473nm

Type I SHG@946nm

BIBO-335-C5/C5

Θ=159.6°φ=90°

3x3x5

AR/AR@914&457nm

Type I SHG@914nm

BIBO-3310-C5/C5

Θ=159.6°φ=90°

3x3x10

AR/AR@914&457nm

Type I SHG@914nm

              

Physical properties:

 

Crystal Structure

Monoclinic,Point group 2

Lattice Parameter

a=7.116Å, b=4.993Å, c=6.508Å, β=105.62° ,Z=2

Physical Axis

X//b,(Z,a)=31.6°,(Y,c)=47.2°

Melting Point

726°C

Mohs Hardness

5-5.5

Density

5.033 g/cm3

Thermal Expansion coefficient

αa=4.8x10-5/K,   αb=4.4x10-6/K,  αc=-2.69x10-5/K

Specific Heat

0.5 J/gm-K at 330 K

Optical Homogeneity

Dn~10-6/cm

Hygroscopisity

non

 

Optical Properties:

 

Transparency Range

286-2500nm

Absorption Coefficient

<0.1%/cm at 1064nm

NLO coefficients (pm/V)

d12=d14=2.3, d25=d36=2.4, d11=2.53,

d13=-1.3, d35=-0.9, d26=2.8

SHG 1064nm

Phase matching angle:168.9° from z axis in YZ plane

Deff:3.0+/-0.1 pm/V

Angular acceptance:2.32 arad-cm

Walk-off angle :25.6 mrad

temperature acceptance:2.17°C-cm

Sellmeier Equations (λ in μm)

n12=3.6545+0.0511/(λ2-0.0371)-0.0226λ2

n22=3.0740+0.0323/(λ2-0.0316)-0.01337λ2

n32=3.1685+0.0373/(λ2-0.0346)-0.01750λ2