CeF3 Crystal
CeF3 crystal has paramagnetic rotation characteristics. Among the rare earth (RE3+) ions, fluoride crystals generally have higher UV-VIS-IR transparency than oxide crystals. At the same time, Ce3+ is characterized by complete transparency in the VIS region. However, the TGG material traditionally used as a Faraday rotator (FR) has a continuous decrease in transparency toward shorter wavelengths in the visible (VIS) wavelength region, resulting in optical loss and loss of equipment performance and other adverse effects. Therefore, in the uncovered UV and VIS wavelength regions, the use of cerium fluoride crystals as FR has considerable potential.
The magneto-optical properties of CeF3 crystal enable it to be used as a Faraday rotator used in the field of high-power lasers
CeF3 crystal is transparent in the spectral range up to 2.5µm. As a consequence, it can be used as a 2µm Faraday device, and similarly, it is a paramagnetic material. In the 1.86 − 2.3 µm spectral range, the Verdet constant is approximately 9–5 rad / Tm (absolute value). In order for the CeF3 crystal to reach the Faraday rotation angle required by the standard, a relatively strong magnetic field or multiple magneto-optical elements will be required. Another significant advantage keeps that the possibility of producing large-aperture (up to ~10 cm) optical elements remain available for CeF3 in high-power laser systems. In this respect CeF3 surpasses most of the magneto-active crystal media. For example, the largest aperture of a TGG single crystal with quality fit for producing an FI is only 40 mm.
Parameter
| Chemical Formula | CeF3 |
| Density (g/cm3) | 6.16 |
| Melting point (℃) | 1443 |
| Refractive index @400nm | 1.62 |
| Lattice Parameter | a=7.112Å |
| Growth Method | Bridgman Stockbarger |
| Transparency | >300nm |
| Verdet Constant(450 nm) | 247 rad/T |
| Verdet Constant(532 nm) | 180 rad/T |
| Verdet Constant(633 nm) | 129 rad/T |
| Verdet Constant(810 nm) | 63 rad/T |
| Verdet Constant(980 nm) | 44 rad/T |
| Verdet Constant(1075 nm) | 33 rad/T |
| Verdet Constant(1310 nm) | 10 rad/T |
| Verdet Constant(1940 nm) | 10.1 rad/T |
| Laser Host Material,Emission Wavelength | CeF3 Crystal,V [rad/Tm] (L45 [mm]) |
| Tm:silica fiber, 1.86 µm | – 9.2 ± 0.1 (∼53.2) |
| Tm:germanate fiber, 1.90 µm | – 8.7 ± 0.1 (∼56.5) |
| Tm:silica fiber, 1.94 µm | – 8.2 ± 0.1 (∼60.0) |
| Tm:YAG, 2.01 µm | – 7.4 ± 0.1 (∼66.5) |
| Ho:YLF, 2.05 µm | – 7.0 ± 0.1 (∼70.5) |
| Ho:YAG, 2.10 µm | – 6.5 ± 0.1 (∼75.9) |
| Tm:YLF, 2.30 µm | – 4.8 ± 0.1 (∼102.2) * 185 ± 15 (∼4.2) |
An L45 length of a magneto-optical element needed for a 45-degree polarization plane rotation is specifified in the brackets for all of the investigated materials.
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CeF3 emission curve | CeF3 transmission curve |
CeF3 crystal case (1)
Size: Dia 5mm, 5mm long;
Polish:the two flat faces polished
- Is transparent up to 2.5 µm and, therefore, it is also used for the 2-µm Faraday devices.
- Has a ∼9–5 rad/Tm (in the absolute value) Verdet constant in the 1.86 6 2.3 µm spectral region.
- Relatively strong magnetic fields or multiple magneto-optical elements would be needed to achieve the standardly needed Faraday rotation angles using the CeF3 crystal, nevertheless, the technology to fabricate this material in large sizes is already available.
- Verdet constant dispersion data in the 2-µm spectral region may be approximated (with a <15% accuracy) by a model, which considers contributions of a single, most dominant electric dipole transition located at approximately 0.234 µm.
Faraday rotator used in the field of high-power lasers
| Bridgman growth and magneto-optical properties of CeF3 crystal as Faraday Rotator Optical Materials Volume100,2019 |
| CeF3 and PrF3 as UV-Visible Faraday rotators Optics Express Volume 19,Issue 12.2011.PP11786-91 |
| Continuous-Wave Cavity Ring-Down Polarimetry The Journal of Chemical Physics,2020 |
| Determination of the Faraday rotation perpendicular to the optical axis in uniaxial CeF3 crystal by using the Generalized-High Accuracy Universal Polarimeter Scientific reports (2019) 9:18453 |
| Faraday Rotation of Dy2O3, CeF3 and Y3Fe5O12 at the Mid-Infrared Wavelengths Materials 2020,13,5324 |
| Linear birefringence, linear dichroism and Faraday rotation of CeF3 single crystal along the perpendicular to the optic axis The 6th Waseda-NIMS International Symposium |
| MAGNETIC FIELD DEPENDENT RESTSTRAHLEN SPECTRA IN PARAMAGNETIC CeF3 JOURNAL DE PHYSIQUE Colloque C6, supplement au n° 12, Tome 42, decebre 1981,page c6-499 |
| Temperature dependence of Faraday rotation and magnetic susceptibility for Ce3+ and Pr3+ ions in fluorozirconate glass Journal of Non-Crystalline Solids 231 (1998) 257-267 |
| Theory of Faraday rotation and susceptibility of rare-earth trifluorides PHYSICAL REVIEW B VOLUME 46, NUMBER 18 ,NOVEMBER 1992-II |
| Thermo-optical and magneto-optical characteristics of CeF3 crystal Optical Materials 69 (2017) 196-201 |
| Ultraviolet-visible optical isolators based on CeF3 Faraday rotator Journal of Applied Physics 117, 233101 (2015) |
| UV-Visible Faraday Rotators Based on Rare-Earth Fluoride Single Crystals_LiREF4(RE=Tb,Dy,Ho,Er and Yb),PrF3 and CeF3 Valentyn Vasyliev et al 2012 Meet. Abstr. MA2012-02 2442 |
| Verdet constant dispersion of CeF3 in the visible and near-infrared spectral range Optical Engineering 56(6), 067105 (June 2017) |
