Beta-Barium Borate
ß-BaB2O4

Structural and Physical Properties

Crystal Structure .

Trigonal, space group R3c

 

 

Cell Parameters

A = b = 12.532 Å

   

C = 12.717 Å

   

Z = 6

   

Melting Point

1095 ± 5°C

   

Transsition temperature

925 ± 5°C

   

Optical homogeneity

δddn ≈ 10-6 /cm

   

Mohs Hardness

4

   

Density

3.85 g/cm³

   

Absorption Coefficient

< 0.1 %/cm ( at 1064 nm )

   

Specific hea:

1.91 J/cm³ x K

Hygrocopic susceptibility

Low

Thermal expansion Coefficients.

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

Linear Optical Properties

Transparency range

189 – 3500 nm

Refractive indices

at 1064 nm

ne = 1.5425

no = 1.6551

at 532 nm

n= 1.5555

no = 1.6749

at 266 nm

ne = 1.6146

no = 1.7571

Therm – optic Coefficients.

dn/ dt = -9.3 x 10-6 /°C

dn/ dt = -16.6 x 10-6 /°C

Nonlinear Optical Properties

Phase – matchable output Wavelenghts

189 – 1750 nm

NLO Coefficients

d11 = 5.8 x d36 (KDP)

d31 = 0.05 x d11

d22 = 0.05 x d11

Electro – Optic Coefficients

γ??11 = 2.7 pm/V, γ??22, γ??31 <0.1 γ??11

Half – wave voltage

48 KV (at 1064 nm)

Damage threshold

at 1064 nm

5 GW / cm² 
(10 ns)

10 GW / cm² 
(1.3 ns)

at 532 nm

1 GW / cm² 
(10 ns)

7 GW / cm² 
(250 ns)

List of Optical Crystals

Materials

Refractive Index

Transmission
Range (mm)

Density
(g/cm³)

Thermal Expansion  
Coefficient (10-6/K) 

 

BK7 glass

1.5164 (588 nm)

0.330 – 2.1

2.51

7.5 

 

SF11 glass

1.78472 (588 nm)

0.370 – 2.5

4.74

6.8 

 

F2 glass

1.62004 (588 nm)

0.420 – 2.0

3.61

8.2 

 

Fused Silica

1.4858 (308 nm)

0.185 – 2.5

2.20

0.55 

 

CaF2

1.399  (5.0 mm)

 0.170 – 7.8

 3.18

 18.85 

 

BaF2

 1.460 (3.0 um)

 0.15 – 12.0

 4.88

 18.4 

 

Sapphire

1.755 (1.0mm)

0.180 – 4.5

3.98

8.4 

 

Silicon

3.4179 (10mm)

 1.200 – 7.0

 2.33

 4.15 

 

Ge

4.003 (10 mm)

 1.900 – 16

 5.33

 6.1 

 

ZnSe

2.40  (10 mm)

0.630 – 18

5.27

7.8 

 

ZnS

2.2 (10mm)

0.380 –14

4.09

6.5 

 

LiF

1.39 (500 nm)

 0.150 – 5.2

 2.64

37 

 

KBr

1.526 (10 mm)

 0.280 – 22

 2.75

43 

 

 MgF2

no =  1.3836
ne = 1.3957 (405 nm)

0.130 – 7.0

7.37

a: 13.7
b: 8.48

 

YVO4

no = 1.9500
ne = 2.1554 (1.3 mm)

0.400 – 5.0

4.22

a: 4.46
b: 11.37

 

Calcite

no =  1.6557
ne = 1.4852 (633 nm)

0.210 – 2.3

2.75

a: 24.39
b: 5.68

 

Quartz

no =  1.5427
ne = 1.5518 (633 nm)

0.200 – 2.3

2.65

7.07

 

α-BBO

no =  1.6749
n= 1.5555 (532 nm)

0.190 – 3.5

3.85

a: 4.0
c: 36

 

LiNbO3

no =  2.2863
ne = 2.2027 (633 nm)

0.370 – 4.5

4.64

a: 16.7
c: 2.0