REDUCING THE OPTICAL-ABSORPTION OF LPE GARNET-FILMS AT A WAVELENGTH OF AROUND 1000NM

This paper concerns the reduction of optical absorption loss L of Bl-s ubstituted rare-earth tron garnet films at a wavelength of around 1000 nm for use as a 45 degrees Faraday rotator of an optical isolator. Fir st, a single crystal of Nd1.21Gd1.74Sc2.07Ga2.38O12, with a lattice co nstant of 1.2619nm, was grown by the Czochralski method. Using this cr ystal as a substrate, Nd1.69Bl1.31Fe5O12 film was grown by the LPE (Li quid Phase Epitaxial) method. The resultant LPE film showed a reduced optical absorption at around 1000nm, because Its optical absorption pe ak at around 900nm due to Fe3+ crystal field transition from (6)A1g to (4)T1g shifted toward short wavelengths. In addition, the LPE film's Faraday rotation coefficient Increased, since Nd, as Bl does, contribu tes negatively to the Faraday rotation. The value of L for the LPE fil m was found to be 2.6dB at a wavelength of 980nm, and 1.0dB at 1017nm.