OPTICAL AND LASER SINGLE CRYSTALS

  • Laser active elements based on GGG:Nd, GSGG:Nd,Cr, YSGG:Nd,Cr, YAG:Ho,Tm,Cr, YSGG:Er, YSGG:Er,Cr single crystals.
  • Optical elements of isolators and Faraday rotators based on TbGG.
  • Passive laser Q switches based on YAG:Cr+4, GSGG:Cr+4 single crystals.
  • Crystals and substrates based on Gd3Ga5O12, Ca,Mg,Zr:Gd3Ga5O12, Gd3Sc2Ga3O12 compounds.

 

FIELDS OF APPLICATION

  • Industrial lasers: elements based on GGG:Nd, GGG:Yb;
  • Medical laser equipment: elements based on YSGG:Er, Cr, YSGG:Er and YAG:Er;
  • Ophthalmologic lasers: elements based on YAG:Ho, Tm, Cr and YSGG:Ho, Tm, Cr;
  • Ranging systems and medical lasers: passive Q switches based on GSGG:Cr4+ and YAG:Cr4+;
  • Systems with high and mean power: elements based on GSGG:Nd, Cr and YSGG:Nd, Cr;
  • TGG-based Faraday rotators and isolators;
  • Fiber lasers and interstage net systems: TGG-based elements;
  • Faraday isolators in fiber-optical communication lines: BiYIG films on GGG:Ca, Mg, Zr substrates;
  • GGG substrates for liquid-phase epitaxy, diameter 76 and 100 mm.

SPECIFICATIONS

Laser active elements

 Parameter/Name  YAG:Nd  GGG:Nd

GSGG:Nd,Cr

YSGG:Nd,Cr

1. Structure

Cubic

2. Spatial group

Ia3d - O10h  (230)

3. Lattice parameter, Å

12,01

12,382

12,560

12,455

4. Density, g/cm3

4,5

7,08

6,439

5,3

5. Dielectric constant

11,7

12,11

-

12,94

OPTICAL PROPERTIES

6. Optical transmission (80%), μm

0,28-5,3

0,3-6,5

-

-

7. Refraction index

1,83

1,945

1,952

-

8. Thermo-optic coefficient, dn/dт 10-6/С

+7,3

-

+9

-

9. Thermal lens  (Ø6,3×75 mm), diopter/kW

0,75

-

1

-

THERMALPHYSIC PROPERTIES

10. Linear expansion coefficient, 10-6/°С

7,8

8,5

8,5

8,1

11. Thermal conduction, W/m°С

11

7,05

9

7,4

12. Thermal capacity, J/g°K

0,587

0,381

0,402

0,534

13. Young modulus, E, GPa

282

225

210

218

14. Poisson ratio, v

0,28

0,28

0,28

0,27

15.Mohs hardness

8,5

7,75-8

-

-

16. Thermal damage parameter, Rт, W/cm

650

-

520

-

17. Fracture stress, бf, MPa

280

240

240

-

18. Ultimate strength, Кс, MPa m 0,5

1,4

-

1,2

-

SPECTROSCOPIC PROPERTIES
  1. Nd+3 radiative lifetime, μs

270

250

300

-

20. Signal transition section, 1019cm2

3,4

2,3-2,9

2,9 (1,5)

(1,5)
  1. Cr3+ radiative lifetime, µm

1530

159

115

145

22. Signal transition section, 1020cm2

-

0,6

0,8

0,63

23. Interaction parameter, CDA(Nd-Сr), 10-38cm6/s

9×10-4

1,11

2,2

1,4

24. Saturation parameter, б/hv, J/cm2

0,75

-

1

  

25. Surface fracture threshold 10 ns imps. (17 ns),J/cm2

 10

-

 (14)

-

26. Volume damage threshold, length 4,65 ns imps., GW/cm2

-

5,56

-

-

27. Pumping relative efficiency (to YAG:Nd)

 1

 2

 2-3

 2-3

GROWTH CONDITIONS

28. Melting temperature, ˚С

1970

1740

1840

1910

29. Growth environment

Vacuum

N2+2 об%O2

N21÷2об% O2

N2-1÷2 об%O2
  1. Neodymium distribution coefficient

0,18

0,65

0,75

0,7
  1. Chrome distribution coefficient

2,4

3,3

1

1,1

32. Neodymium ion concentration, аt.%

1

1-3

2

2

Neodymium ion concentration, 1020 cm-3

0,5

1÷3,5

2

2-3

33. Chrome ion concentration, 1020 cm-3

-

-

2

1-2
                 

Passive laser Q-switches

Parameter

Crystal type

GSGG: Cr4+

YAG: Cr4+

Physical properties

Chemical formula

Gd3Sc2Ga3О12: Cr4+

  

Structure

CUBIC

Spatial group

Ia3d – O1h (№ 230)

Density

6.48

4.5

Optical properties

Optical transmission (80%), µm

0.3 - 6.5

Refraction index in 1.064 µm

1.96276

1.83

Thermo-optical coefficient, 10-6/°C

9.04

7.3

Thermal damage theshold, W/cm

> 5

7.9

Service properties

Wavelength, µm

0.9-1.2

Initial transmission at operating wavelength length

10 - 80%

Initial absorption coefficient, cm-1

16

2-3

Contrast coefficient

6-15

Process-dependent parameters

Orientation axis

[100] or [111]  ±  l5'

Size, mm                 diamerer

                               length

5 – 20   ±0.025

1 – 10   ±0.250

End faces parallelism, s

10

End faces perpendicularity, min

5

Flatness

1/10th wavelength

Front surface finish

P IV State Standart 11141-84

Side surface finish, µm

60-80
       

Optical isolating materials

 Parameter

Crystal type

TGG

Chemical formula

Тb3Gа5O12

Structure

CUBIC

Spatial group

Ia3d-О10h   (№230)

Lattice parameter, Å

12.347

Thermal conductivity, Wm-1K-1

4.5

Refraction index            1060 nm

                                    600 nm

1.954 

1.978
Dielectric constant

12.40 ±0.03

Dielectric loss, tan σ

0.0005

Optical transmission, at 500-1400 nm

> 99 %

Absorption coefficient, at 1060 nm,  cm-1

≤0.0025

Verdet constant, at 500 – 1060 nm min щукsted-1, cm-1

  1. 633 nm

at 1058 nm

0.75 - 0.12

0.46

0.1272

Birefringence, %

≤ 0.01

Loss factor, dB

>30

Perfection factor, at 633 nm,  min/dB

1.5

Impulse damage threshold, MW cm-2

>300

Breakdown threshold in nonrecurrent mode at pulse duration 1 ns of single-mode beam of diameter 2 mm, J/cm2

 7-8

Crystallographic axis orientation

[100] or [111] ±15'

Size, mm:

diameter

length

2 - 30

5 - 50

Side surface finish by diamond wheel, µm

60-80

Substrate crystals

Parameter

Crystal type

GGG: Ca, Mg, Zr

GSGG

GGG

Structure

CUBIC

Spatial group

la3d – О10h (№  230)

Chemical formula

Gd3-xCaxGa5-x-2yMgyZrx+yO12

Gd3ScxGa5-xO12

Gd3Ga5O12

Density, g/cm3

6.72

6.48

7.07

Melting temperature, K

1720

1840

1740

Dielectric constants

10

10

  

Lattice parameters, Å

12.493 ± 0.002

12.563 ± 0.002

12.383 ± 0.002

Linear expansion coefficient, 10-6/°C

7

6.5

  

Refraction index at 26.0°±0.4

6438.47 Å

10640.00 Å

(y=0)

1.94941

1.93894

1.96276

1.94203

1.945

Thermal conductivity, Wm-1K-1

5.03

6.4

  

Thermo-optical coefficient, 10-6/C° at 1.152 µm2

12.45

9.04

  

Color

colorless

Diameter, mm

76 ± 0.25

176.2±0.25,   101.6 ± 0.25

Thickness, µm

500 ± 20

Orientation

[111], [100] ±15' or other

Primary flat

(ĪI0)±2.0

Secondary flat

(ĪĪ2), 90±5° from primary flat

Flatness

< 5 µm on 80% of wafer area

Defect density, cm-2

0 -10

0.5