1. A scannerless three-dimensional (3-D) imaging apparatus to provide a 3-D image of a target within a field of view, comprising: a continuously-emitting light source which is amplitude modulated in response to a first sinusoidal modulation signal at a frequency f 0 to provide a non-scanned illumination of the field of view; a loss modulator which is modulated at the same frequency f 0 in response to a second sinusoidal modulation signal having a variable phase delay with respect to the first sinusoidal modulation signal, with the loss modulator being adapted to receive light backscattered from the target within the field of view and to provide a loss in transmission through the loss modulator which is range dependent and phase-delay dependent; and an array detector to detect the backscattered light transmitted through the loss modulator and generate therefrom an electrical output signal containing information wherefrom the 3-D image of the target can be constructed.