TGG Faraday Crystals High Thermal Conductance Laser Damage Threshold

Description

Terbium gallium garnet (Tb3Ga5O12, TGG) is a crucial category of magneto-optical materials for use in the visible and the near-infrared spectral regions((400-470nm and 500-1500nm)). The TGG crystal possesses a large Verdet constant (35 RadT−1m−1 at 1064 nm), high thermal conductivity (7.4 Wm−1K−1), low optical losses (< 0.1%/cm) and high laser damage threshold (> 1 GW/cm2). Therefore, it is an attractive Faraday-rotating crystal suitable for constructing magneto-optical isolators, magneto-optical switches, magneto-optical modulators and so on,widely used in YAG, Ti-doped sapphire and other multi-stage amplification, ring type, seed injection laser.

Feature

• Large Verdet Constant (35 Rad T-1m-1).
• Low optical losses (<0.1%/cm)
• High thermal conductivity (7.4W m-1K-1).
• High laser damage threshold (>1GW/cm2).
• TGG has twice the Verdet constant of a terbium-doped glass.
• Thermal conductivity is an order of magnitude greater than typical glass.
• Optical losses are lower for TGG than Tb-doped glasses.

Application

Famagneto-optic waveguide based on TGG crystal via 15 MeV C3+ ion irradiation. The ion irradiation process leads to the optical anisotropy in the as-irradiated TGG waveguide,which hinders the magneto-optical rotation in the waveguide. To remove the irradiation-induced optical anisotropy, we annealed the as-irradiated TGG waveguide under different conditions. After annealing at 400°C for one hour, the magneto-opticalrotation of 14° per centimeter is observed in the waveguide at the wavelength of 632.8nm, under the magnetic field of 0.24T, which is comparable to that observed in the TGG crystal under the same magnetic field.

Ion irradiated magneto-optic waveguide based on TGG crystal

Parameter