An integrated optical phased array includes an input channel receiving an optical input signal, and a multitude of signal processing channels each adapted to supply an associated optical output signal along a first axis in response to the input signal. Each signal processing channel includes, in part, a phase modulator adapted to modulate the phase of the signal travelling through the channel, thereby to control or steer the output signal of the phased array. Each channel optionally includes first and second photo detection circuits respectively generating first and second detection signals. The first and second detection signals in each channel may be used to modulate the amplitude and/or phase of the output signal of that channel thereby to control and steer the output signal of the phased array.