Difference Between TGG and TSAG Magneto-Optical Crystals
31 Jul.,2025
TGG vs TSAG", "magneto-optical crystal for fiber laser", "best Faraday isolator crystal"
Difference Between TGG and TSAG Magneto-Optical Crystals
TGG (Terbium Gallium Garnet) and TSAG (Terbium Scandium Aluminum Garnet) are both magneto-optical crystals widely used in Faraday isolators and rotators. The key differences between them are as follows:
1. Chemical Composition
- TGG (Terbium Gallium Garnet): Composed of Tb₃Ga₅O₁₂.
- TSAG (Terbium Scandium Aluminum Garnet): Composed of Tb₃Sc₂Al₃O₁₂, with Ga partially substituted by Sc and Al.
2. Magneto-Optical Performance (Faraday Effect)
- TGG exhibits a high Verdet constant but is less effective at longer wavelengths.
- TSAG has a higher Verdet constant at wavelengths above 1000 nm, making it more suitable for fiber laser applications.
3. Optical Transparency
- TGG provides high transmission in the 400 nm - 1100 nm range.
- TSAG offers a broader transmission range of 400 nm - 1600 nm, making it more efficient for long-wavelength applications.
4. Main Applications
- TGG is commonly used in Faraday isolators for 532 nm and 1064 nm laser systems.
- TSAG is ideal for fiber lasers and high-power laser systems operating at 1030 nm, 1064 nm, 1310 nm, and 1550 nm.
5. Suitability for Laser Systems
| Parameter | TGG | TSAG |
|---|---|---|
| Chemical Composition | Tb₃Ga₅O₁₂ | Tb₃Sc₂Al₃O₁₂ |
| Verdet Constant | High (Visible – Near-Infrared) | Higher at wavelengths >1000 nm |
| Transmission Range | 400 nm – 1100 nm | 400 nm – 1600 nm |
| Suitable Wavelengths | 532 nm, 1064 nm | 1030 nm, 1064 nm, 1310 nm, 1550 nm |
| Main Applications | Nd:YAG laser systems, Faraday isolators (532/1064 nm) | Fiber lasers, high-power laser systems |
Conclusion
- TGG is recommended for 532 nm and 1064 nm laser systems.
- TSAG is the preferred choice for fiber lasers and high-power laser systems operating in the 1030 nm - 1550 nm range.
Both materials have unique advantages, and selection should be based on the required wavelength, power handling, and system compatibility.
