Faraday rotator glass is a kind of magneto-optical glasses with good transmittance in the visible and infrared range（520～1400nm）. Faraday rotator glass is more suitable for medium and low power level lasers, and is cheaper compared with the other magneto-optic crystals such as TGG,TSAG. TG20 has been used widely in switch, modulator, sensor, magneto-optical isolator.
| Diameter Tolerance | < λ/8 @ 633nm | |
| Length Tolerance | ±0.05mm | |
| Flatness | <λ/8 @ 633nm | |
| Surface Quality | 10/5 scratch/dig | |
| Parallelism | < 5 seconds | |
| Clear Aperture | >90% | |
| Edge Chamfer | 0.1mm x 45° |
Physical and Chemical Properties
| Materials | TG20 | TG28 |
| Thermal Coefficient of Refractive Index (10-7 /℃) | 74 | – |
| Thermal Coefficient of Optical Path (10-7 /℃) | 105 | – |
| Transmission Window (nm) | 520-1400 | 520-1400 |
| Coefficient of Thermal Expansion (10-7 /℃) | 51.3 | 69 |
| Transition Temperature (℃) | 760 | 759 |
| Sag Temperature (℃) | 800 | 800 |
| Density (g/cm 3 ) | 4.32 | 4.99 |
| Young’s Modulus GPa) | 108 | |
| Poisson’s Ratio | 0.22 | |
| Knoop Hardness (Kg/cm2 ) | 760 |
Optical and Spectral Properties
| Materials | TG20 | TG28 |
| Refractive Index (1064nm) | 1.6721 | 1.736 |
| Refractive Index (d 589.3nm) | 1.6888 | 1.75 |
| Nonlinear Refractive Index (10-13 e.s.u .) | 2.46 | 2.42 |
| Abbe Number | 53.14 | 50.98 |
| Materials | TG20 | TG28 |
| Verdet Constant V (min/Oe.cm): 632.8nm | -0.258 | -0.361 |
| Verdet Constant V (min/Oe.cm): 1064nm | -0.075 | -0.106 |
High verdet constant
Good chemical durability
Excellent transparency
Extinction ratio tester
Raman Fiber amplifier module
Magneto optical switch
Magneto-optical modulator
Magneto-optical isolator