Silica sol gel micro-lasers and methods of fabricating micro-lasers on a chip or a wafer. A silica sol gel micro-laser includes a silica sol gel optical micro-cavity, a substrate, and a support member or pillar that extends between the micro-cavity and the substrate. An outer surface or periphery of the micro-cavity extends beyond a top of the sol gel support member or is overhanging with respect to the underlying support member. Optical energy travels along an inner surface of the silica sol gel micro-cavity. Undoped silica sol gel micro-cavities can be used for Raman lasers. Sol gel micro-cavities can be doped with, for example, erbium, and can be used for erbium-doped micro-lasers that have ultra narrow line widths, for example, less than 100 Hz. Undoped and doped silica sol gel micro-lasers can have Q factors greater than 107.