3D imaging of passive objects using dual-sided phase conjugating sequentially switched lens

In this paper we introduce a new concept of a dual sided phase conjugating lens operating as an imaging sensor for continuous wave or pulsed signals for passive target 3D localization. We describe the principle of operation and demonstrate the core resolution properties for single and multiple objects by the way of numerical simulation. Particularly it is shown that the characteristic resolution of a single target by the lens operating under Gaussian pulse excitation is approximately the same as that obtained using UWB synthetic aperture radar techniques. The present concept offers major advantages with respect to existing time reversal techniques which involve computationally expensive high speed digital signal processing of the scattered field. The lens only requires hardware to collect the field scattered from the target(s) and to refocus it onto these target(s). This property should be of high potential for imaging applications where refocusing has to be accomplished in a real time i.e. when high speed target acquisition is necessary. Alternatively the lens can be operated in conjunction with a conventional imaging regime, i.e. to collect the scattered field data, send it to a post processing unit for mathematical image localization.