This SBIR Phase I project will develop efficient, scalable and low-cost photo-bioreactors with light guiding optical sheets and low-power spatial light modulators to increase culture density and light penetration, and decrease doubling time for the production of microalgae. This proposed research will enhance the algal growth in a photo-bioreactor by using a low-power spatial light modulator to effectively reduce the photon saturation effects and light guiding optical sheets to guide photons to the interior of a photo-bioreactor. The broader/commercial impact of the project will be the improved efficiency of a photo-bioreactor for the production of microalgae by reducing the photon saturation effects and guiding photons to the interior of a photo-bioreactor. The technology to be developed by this project should be attractive to provide efficient and low-cost photo-bioreactors to the algal industry