NOVELTY - The optofluidic photobioreactor comprises optical waveguides having an input characterized by an evanescent optical field confined along an outer surface of the optical waveguide produced by radiation propagating in the optical waveguide, a unit for inputting light to the input of the optical waveguide, a selected photosynthetic microorganism disposed within the evanescent field, a photobioreactor enclosure having an input and an output inside of which the optical waveguides are disposed, a liquid microorganism-nutrient media, and a controller.    USE - The optofluidic photobioreactor is useful for optically exciting a photosynthetic microorganism for generating a biofuel, a biofuel pre-cursor or a biomass from the optically-excited photosynthetic microorganism (claimed).    ADVANTAGE - The optofluidic photobioreactor provides precise control over the cultivation environment and effective light distribution to cells by spatially diluting the light over a larger surface area, and maintains growth conditions.    DETAILED DESCRIPTION - The optofluidic photobioreactor comprises optical waveguides having an input characterized by an evanescent optical field confined along an outer surface of the optical waveguide produced by radiation propagating in the optical waveguide, a unit for inputting light to the input of the optical waveguide, a selected photosynthetic microorganism disposed within the evanescent field, a photobioreactor enclosure having an input and an output inside of which the optical waveguides are disposed, a liquid microorganism-nutrient media, a controller operably connected to the photobioreactor enclosure, a microfluidic chip in or on which the optical waveguides are disposed, and an artificial adhesive disposed intermediate to the outer surface of the waveguide and the selected photosynthetic microorganism such that the microorganism is adhered to the outer surface of the waveguide. The optical waveguide is an unclad optical fiber (101) having a diameter of 10-100 mu m, an input end, a multi-mode optical fiber, and a corrugated sheet waveguide. The optical waveguides are disposed in a side-by-side array configuration, and have a center-to-center intra-waveguide separation (D), where d less than or equal to D less than or equal to 1.5d. The photobioreactor enclosure is characterized by optically-dark fluid channels created by a void space surrounding the optical waveguides. The optical waveguides comprise a prism waveguide. The light inputting unit comprises a laser output directly inputted to the prism waveguide, and solar radiation channeled to the input of the optical waveguide. The liquid microorganism-nutrient media is disposed in the void space. The photosynthetic microorganism consists of a bacterium such as cyanobacterium, which is Synechococcus elongatus, and algae or is a genetically-engineered, direct biofuel-producing microorganism. The microfluidic chip is in the form of a high aspect ratio (thin) corrugated sheet. The selected photosynthetic microorganism is in the form of an adsorbed single layer of the microorganism. An INDEPENDENT CLAIM is included for a method for optically exciting a photosynthetic microorganism for generating a biofuel, a biofuel pre-cursor or a biomass from optically-excited photosynthetic microorganism.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a photobioreactor system.    Unclad optical fibers (101)    Photobioreactor system (200)    Solar collectors (202)    Reactor enclosure (207)    Control component. (237)