Multicolor and white lasers from semiconductor nanomaterials

We report on our recent research on demonstrating the simultaneous lasing in red, green and blue from a single monolithic nanosheet. The careful adjustment of relative output intensities of these elemental colors leads to an overall white appearance from a single laser structure. Larger tolerance to mismatch at nanoscale offers unique opportunity of growing monolithic semiconductor alloy structures of very dissimilar lattice constants and bandgaps. The wide range of available bandgaps from a single high quality nanostructure allow for simultaneous lasing in multiple colors such as red and green [1.2], or in all three elemental colors [3]. The flexibility of the materials and the structures allow the control of relative intensities of each individual colors, such that the overall color can appear as any visible colors in the triangular color gamut, especially as white. Such a monolithic multi-color or white laser can be potentially useful for many applications. In this talk, our recent efforts in growth and characterization of such unique nanostructures of alloy semiconductors to achieve lasing in white and multiple colors will be presented, together with demonstration of various lasing configurations. Some possible applications will be also discussed.