Laser Crystal

Physical   and Optical Properties

Chemical   formula

Ti 3+   : Al₂O₃

Nd:Y₃ A_l5 O₁₂

Nd:YVO₄

Crystal   structure

Hexagonal

Cubic

Zircon   Tetragonal, space group D4h,

Melting   point

2050°C

1970°C

Density

3.98   g/cm³

4.56   g/cm³

4.22   g/cm³

Mohs   hardness

9

8.5

Glass-like,   ~5

Thermal   conductivity Coefficient

0.11   cal/(°C x sec x cm)

14 W/m   /K @20 °C, 10.5 W /m /K @100 °C.

||C:   5.23 W/m/K; ^C: 5.10 W/m/K

Thermal   Expansion Coefficient

7.8 x   10-6 /K [111], 0 - 250 °C

a_a=4.43x10^-6/K,   a_c=11.37x10-6/K

Lasing   Wavelength

660~1050   nm (795 nm)

1064   nm

914nm,   1064 nm, 1342 nm

Absorption   range

400~600   nm (488 nm)

lamp   pump

808nm

Lattice   constants

a=4.748,   c=12.957

12.01

a=b=7.12,   c=6.29

Fluorescence   lifetime

3.2   µsec (T = 300 K)

230msec

90   msec (about 50 m s for 2 atm% Nd doped) @ 808 nm

Absorption   Coefficient

1.0~7.5cm ^-1@490nm

7.1 cm^-1

31.4   cm ^-1 @ 808 nm

Refractive   index

1.76 @   800 nm

1.82   @1064nm

n_o =1.9573,   n_e=2.1652 @ 1064nm

Polarized   Emission

Unpolarized

Unpolarized

parallel   to optic axis (c-axis)

Typical   Specification and Tolerance

conentration

0.06~0.5   wt% Ti dopant

0.5~1.2   atm% Nd dopant (10% tolerance)

0.2 ~   3 atm% Nd dopant (10% tolerance)

Figure   of Merit

100~300

Aperature

2~50mm

3 ~   14mm

1 ~   20mm

Path   Length

2~130mm

1 ~   160mm

0.02 ~   20mm

End   configuration

flat/flat   or Brewster/Brewster ends or Specified

flat/flat   or Brewster/Brewster ends or Specified

flat/flat   or Brewster/Brewster ends or Specified

Orientation

Optical   axis C normal to rod axis

<111>   crystalline direction (+/-0.5°C)

a-cut   crystalline direction (+/-0.5°C)

parallelism

<λ/10   arc seconds

Surface   quality

better   than 60/40 scratch/dig per MIL-O-13830A

better   than 20/10 Scratch/Dig per MIL-O-1380A

better   than 20/10 Scratch/Dig per MIL-O-1380A

Surface   flatness

<λ/10   @633nm

<λ/10   at 632.8nm

<λ/10   at 632.8nm

Wavefront   distortion

<λ/4   per inch @ 633 nm

<λ/10   at 632.8nm for 3 ~7mm
            <λ/8 per inch at 632.8nm for >=7mm

<λ/8   at 633nm

Perpendicularity

< 5   arc minutes

< 5   arc minutes

< 5   arc minutes

Clear   aperture

Central   90%

Central   95%

Central   95%

Chamfer

0.15x44°

0.15x45°

0.15x45°

Damage   threshold

over   15J/cm² (rods without coating) 
            over 700MW/cm²(coating)

over   15J/cm² (rods without coating) 
            over 700MW/cm²(coating)

over   15J/cm² (rods without coating) 
            over 700MW/cm²(coating)

Coatings

AR@700~1100nm

a)   AR@1064nm,R<0.1%
            b) AR@1064nm,R<0.1%;
            HT@808nm,T>95%;
            c) HR@1064nm,R<99.8%;
            HT@808nm,T>95%;
            d) HR@1064nm,R<99.8%;
            HT@808nm,T>95%;
            HR@532nm,R>99%;

a)   AR@1064nm,R<0.1%
            b) AR@1064nm,R<0.1%;
            HT@808nm,T>95%;
            c) HR@1064nm,R<99.8%;
            HT@808nm,T>95%;
            d) HR@1064nm,R<99.8%;
            HT@808nm,T>95%;
            HR@532nm,R>99%;