High speed microsecond domain switching optical delay lines are introduced for time-delay based photonic signal processing applications such as phased array control and transversal filtering. These delay lines use acousto-optic deflectors for both optical delay path selection and optical beam realignment, producing inherently self-aligning control architectures. Both transmissive and reflective designs are introduced that can operate with either fiber, free-space, and solid-optic delay paths. High accuracy analog tuning of both beam position and beam optical power are possible with these modules. (C) 1998 Elsevier Science B.V.High speed microsecond domain switching optical delay lines are introduced for time-delay based photonic signal processing applications such as phased array control and transversal filtering. These delay lines use acousto-optic deflectors for both optical delay path selection and optical beam realignment, producing inherently self-aligning control architectures. Both transmissive and reflective designs are introduced that can operate with either fiber, free-space, and solid-optic delay paths. High accuracy analog tuning of both beam position and beam optical power are possible with these modules. (C) 1998 Elsevier Science B.V.