TGG (Terbium Gallium Garnet Crystal)
TGG crystal is an excellent magneto-optical crystal used in various Faraday devices(Polarizer and Isolator) in the range of 400nm-1100nm, excluding 475-500nm.
Advantages
· TGG has twice the Verdet constant of a terbium-doped glass.
· The thermal conductivity of crystalline TGG is an order of magnitude greater than a typical glass.
· Optical losses are lower for TGG than Tb-doped glasses.
· The combination of the above factors make TGG better suited to high average power applications. The principal limiting factor is thermally induced beam distortion. Beam distortion is less for TGG than Tb-doped glasses under the same power loading level.
Properties:
|
Formula
|
Tb3Ga5O12
|
|
Crystal Structure
|
[111]
|
|
Verdet Constant (632 nm)
|
-134 RadT-1m-1
|
|
Verdet Constant (1064 nm)
|
-40 RadT-1m-1
|
|
Thermal Conductivity
|
7.4 W cm-1 K-1
|
|
Refractive Index
|
1.95
|
|
Nonlinear Index, n2
|
8
|
|
Figure of Merit, V/a
|
27
|
|
Figure of Merit, V/n2
|
5
|
Specifications:
|
Orientation
|
[111] within ±15 arc min
|
|
Wave Front Distortion
|
< 1/8 wave
|
|
Extinction Ratio
|
> 30dB
|
|
Diameter
|
+0.00mm/-0.05mm
|
|
Length
|
+0.2mm/-0.2mm
|
|
Chamfer
|
0.1mm @ 45°
|
|
Flatness
|
< 1/10 wave at 633nm
|
|
Parallelism
|
<10 arc secs
|
|
Perpendicularity
|
< 5 arc min
|
|
Surface Quality
|
10/5 Scratch/Dig
|
|
AR coating
|
R<0.2% AR @1064nm
|
|
Barrel Finish (10-6 inches)
|
55 ± 5
|
Attached following Extinction Ratio measurement reports:
