Initial development of an integrated optoelectronic probe for biomedical imaging

There has recently been increased interest and progress in the development of medical diagnostic techniques based on the optical properties of tissues (e.g. optical absorption and scattering at different wavelengths) and various substances of interest (e.g. fluorescence of intra-cellular structures, drugs, or dyes). Many applications could be envisaged for an optical probe or imaging system that is both inexpensive and small enough to be portable or even implantable. However, current systems do not meet these two criteria, as they are generally constructed using discrete components. We present an integrated circuit implementation of an optical probe, where a detector and receiver circuit are fabricated together on a single chip in a standard analog CMOS process. The advantages of an integrated probe, as opposed to a more conventional optical fiber-based approach, include improvements in light collection efficiency, signal to noise ratio, size, and cost.