It is the terbium doped borosilicate glass and key component of Faraday Rotators and Optical Isolators for visible and near-IR spectral range in high power laser system and fiber-optic communication area.
It is a new important transparent optical glass material. It can be used to produce Optical Isolators, circulators, magneto-optical modulators, optical switches, new generation current sensors, magneto optical fiber etc. Above devices have the characteristics of advance technology, stable performance, high sensitivity, high anti-interference, high insulation etc.
Comparing to TGG crystal, it can made in much larger size(aperture) at lower price. Furthermore, it won't appear the birefringence as the anisotropy in crystal and can be processed in complex shape, such as magneto-optical fiber.
Paramagnetic Faraday Rotator Elements MOE-1:
Data inspected at 20℃
Verdet Constant: -0.313min/Oe*cm or -91rad/T*m at 632.8 nm
Verdet Constant: -0.096 min/Oe*cm or -28 rad/T*m at 1064 nm
Transparence rate ≥ 85% (Uncoated)
Index of Refraction
nD( at 589.3 nm) =1.7464
Optical Quality(△n) /cm < 2x10*-6
Non-linear refractive index n2 (x10*-13 e.s.u.)=2.55
Transformation temperature Tg: 788℃
Sag temperature Ts: 825℃
Coefficient of linear thermal expansion: 63.2×10*-7/℃
Absorption coefficients < 0.001/cm at 632.8nm and 1064nm.
Bulk laser damage threshold > 25 (J/cm*2) 10 ns pulse width at 1064 nm
Chemical properties: excellent
Available in very large rods/ plates / disks
Flatness of two faces: λ /8 wavelength at 632.8nm
Surface quality of two faces: 20-10 scratch/dig (MIL-0-13830A)
Parallelism: <30 arc seconds
Perpendicularity: < 0.5 degree
Diamagnetic Faraday Rotator Elements MOE-2:
Diamagnetic materials generally offer lower Verdet constant, hence lower measurement resolution, but they have better environmental stability, particularly temperature stability comparing to paramagnetic Faraday Rotator elements. For that reason, diamagnetic materials, especially diamagnetic glasses in bulk and fiber for, are commonly chosen as the sensing element in high stability Faraday effect sensor(Williams et al., 1991)
Type 1: Verdet Constant: 0.071 min/Oe*cm or 20.64 rad/T*m at 632.8 nm
Type 2: Verdet Constant: 0.093 min/Oe*cm or 27.1 rad/T*m at 632.8 nm
Index of Refractive Nd(589.3nm): 1.9180
Dispersive index: 21.52
The Verdet constant of a diamagnetic medium depends only upon the dispersion curve of the medium and is not affected appreciably by mechanical or temperature effects. Diamagnetic Faraday Rotator Element is widely used in Magneto Optic Current Transformer(MOCT) and many other instruments.