High speed (microsecond domain) narrowband optical beamforming for ultrasonic frequencies is demonstrated using space-time multiplexing to overcome the slow (millisecond domain) response of ultracompact analog control birefringent-mode nematic liquid crystal devices. (C) 1998 Elsevier Science B.V.High speed (microsecond domain) narrowband optical beamforming for ultrasonic frequencies is demonstrated using space-time multiplexing to overcome the slow (millisecond domain) response of ultracompact analog control birefringent-mode nematic liquid crystal devices. (C) 1998 Elsevier Science B.V.