TGG is an excellent magneto-optical crystal used in various Faraday devices (Rotator and Isolator) in the range of 400nm-1100nm, excluding 475-500nm.
The Faraday rotator consists of a TGG rod contained inside a special designed magnet. The rotation sense of the polarization of a light beam passing through the rotator only depends on the direction of the magnetic field rather than on the direction of propagation of the light beam. The optical isolator is a Faraday rotator set between two suitably aligned polarizers which allows a light beam to pass through in one direction only. TGG has a combination of excellent properties such as large Verdet constant, low light loss, high thermal conductance and high light damage threshold which makes it a unique and attractive material for Faraday devices particularly suitable for fiber lasers and Ti: sapphire tunable lasers, ring type lasers and seed injected lasers.
Main Advantages:
• Large Verdet constant (35 Rad T-1 m-1)
• Low optical losses (<0.1%/cm)
• High thermal conductivity (7.4W m-1 K-1).
• High laser damage threshold (>1GW/cm2)
Main Properties:
| Chemical Formula | Tb3Ga5O12 |
| Lattice Parameter | a=12.355Å |
| Growth Method | Czochralski |
| Density | 7.13g/cm3 |
| Mohs Hardness | 8.0 |
| Melting Point | 1725℃ |
| Refractive Index | 1.954 at 1064nm |
| Thermal conductivity W/( °C*cm) | 7.4W cm-1K-1 |
| Polarized light magnetic constant rotation | 0.12min/Oe.cm at 1064nm |
Specifications:
| Orientation | [111],±15′ |
| Wavefront Distortion | ＜λ/8 |
| Extinction Ratio | ＞35dB |
| Diameter Tolerance | +0.00mm/-0.05mm |
| Length Tolerance | +0.2mm/-0.2mm |
| Chamfer | 0.10mm @ 45° |
| Flatness | ＜λ/10 at 633nm |
| Parallelism | ＜30″ |
| Perpendicularity | ＜5′ |
| Surface Quality | 10/5 |
| AR coating | ＜0.2% |