Wide angle laser beam steering

An investigation of wide angle laser beam steering by stripe domains in certain magnetic crystals has been conducted. Stripe domains were observed in bismuth substituted rare earth iron garnet crystals and MnBiSb crystals. The optical efficiency of diffraction by the bismuth substituted garnet was observed to be more than a factor of 20 greater than the efficiency of YIG crystals at 6328A. A laboratory steering device having a flat drive coil and a BiYbIG crystal with one side reflective coated produced steering through 350 mr(20 degrees) from the residual at a drive power of 37 watts. Improvement in the crystal element would reduce the drive power by perhaps a factor of 10. The influence of triaxial crystalline anisotropy in (111) crystals was calculated and the method of normal field correction is discussed. (Modified author abstract)