Beam steering of a 10. 6‐&mgr;m guided‐wave mode in an electro‐optic GaAs thin‐film waveguide is observed. The deflection angle increases linearly with increasing voltage and interaction length. A switching time of about 60 nsec has been obtained and is limited by the detector response. This technique has been used to obtain more than 12&percent; amplitude modulation of a CO2laser by applying only 50 V to an ∼20‐&mgr;m‐thick GaAs thin‐film waveguide having a total interaction length of 0. 5 cm.