Colossal magneto-optical modulation at terahertz frequencies by counterpropagating femtosecond laser pulses in Tb_3Ga_5O_12

Abstract

Single-frequency terahertz modulation of the magneto-optical Faraday effect with a record amplitude of the polarization rotation of ∼0.5° is achieved using a slab of the etalon Faraday rotator crystal Tb3Ga5O12. The modulation is the result of the interaction of two counterpropagating laser pulses via the optical Kerr effect. The frequency of the modulation is determined by the applied magnetic field and is continuously tunable in a terahertz frequency range between 0 and 0.7 THz.