Large size rare earth iron garnet single crystals grown by the flux-Bridgman method

Rare earth garnet(R_(3)Fe_(5)O_(12),RIG)single crystals are the most ideal magneto-optical medium for optical isolators for wavelength longer than 1.1μm,which has been commercially used in optical fiber communications.However,it is still a great challenge to grow large size RIG single crystals.In this work,highquality Y3 Fe5 O12(YIG)and Bi_(0.9)Tb_(2.1)Fe_(5)O_(12)(Bi:TIG)single crystals were successfully grown by the flux-Bridgman method for the first time.The as-grown crystals up to 20 mm in diameter was obtained using the PbO-B_(2)O_(3)flux.The transmittance of YIG crystals is over 75%in the region of 1100-2500 nm.TIG crystals also have good transmittance in the range of 1100-1700 nm,and show typical Tb absorption from 1700 to 2500 nm.The specific Faraday rotations of YIG and Bi_(0.9)Tb_(2.1)Fe_(5)O_(12) crystals are 185(°)/cm and-1250(°)/cm at 1550 nm,which are comparable to the commercial RIG crystals grown by LPE method.The present results indicate that flux-Bridgman method shows great potential to grow large size and high-quality RIG magneto-optical crystals.