PHOTONICS OF THE NEW MILLENNIUM IN BIOSCIENCE

More than a half century ago and on behalf of biologists, Richard Feynman in a famed lecture asked physicists and engineers to make microscopes 100 times better. It is unfortunate that the most central and fundamental questions of biology remain hitherto unanswered because; as Feynman has put it, we still cannot just look at the subject of our question. The aim of this paper is to highlight the prominent role that the science of photonics can play in the new millennium trying to provide a good vision of cellular and intracellular world. First, the recent solutions that can address the challenges of visualizing the miniature world of micro-organisms are discussed. Then, more emphasis is put on the integral-imaging technique which seems to be the best candidate for visualizing the cellular world as it is able to stimulate the human visual system and thus can construct a high quality three-dimensional image of the cellular structure. Two methodologies, one based on the geometrical optics and the other on the wave optics, are presented to explicate the essence of integral imaging. These approaches have been proposed in the electrical engineering department of Sharif University. Since the resolution of the three-dimensional imaging techniques is limited and since the stimulation of the human visual system becomes meaningless at the sub-cellular level, the final section of the paper is devoted to some recent achievements in nano-photonics, which can help biologists in observing within the cellular world and in reaching out to the single molecule level.