This Small Business Innovation Research Phase I project will develop, test and establish the feasibility of an innovative numerical imaging algorithm, the so-called Elliptic Systems Method (ESM), for the case of frequency-resolved data in Optical/Diffusion Tomography. The strategic goal is to build and market an Optical Mammography device. In pursuing this goal, in the ESM has decisive advantages over other competing imaging algorithms in Diffusion Tomography, such as high speed, robustness, and accuracy. This method has previously proven excellent for the more costly time-resolved data. The code will be tested on both simulated and experimental data. The mathematical tools will be developed in parallel with the development of an experimental hardware device (funds raised from private investors will be used for the hardware side). The principal commercial application of company's interest is in optical mammography. The technique which will be developed in this project is also applicable to optical imaging of targets in foggy atmosphere, optical imaging of underwater mines, nondestructive evaluation, etc.