US Patent 6879606 Intracavity doubled laser

An optical device has a first medium that produces more photons that exit the first medium than enter the first medium, such as a gain material. A second medium that produces light of a different wavelength than the wavelength of light incident thereon, such as a second harmonic generator. The optical device defines a cavity including the first medium and the second medium. An energy source provides energy to at least one of the first medium and the second medium so that light exits the cavity, the energy source is modified in a number of different manners such that the optical device has decreased noise output.