High efficiency intracavity doubled laser and method

Abstract

An intracavity doubled single longitudinal mode laser is disclosed which provides stable (i.e., low amplitude variation in its output beam intensity), efficient operation. An associated method is also disclosed. The laser includes an input mirror and an output mirror defining a resonant cavity and a light path within the resonant cavity and between the mirrors. The output mirror is configured to be substantially transparent to an output wavelength produced within the cavity. A lasant material is positioned in the light path for producing light at a desired fundamental wavelength and possibly other, unwanted wavelengths. Polarizing element and a type I doubling material are also positioned in the light path. During operation of the laser, the polarizing element polarizes the desired fundamental wavelength as well as the unwanted wavelengths of light produced by the lasant material. The type I doubling material then produces output wavelengths at twice the frequency of any wavelengths passing therethrough. The type I doubling material and the polarizing element are arranged such that they cooperate in a way which causes the unwanted wavelengths to be subjected to losses which result in the unwanted wavelengths being extinguished while the desired fundamental wavelength is subjected to a level of loss above a lasing threshold so that the desired fundamental wavelength lases, thereby producing the desired output wavelength. In one aspect of the invention, blue light may be produced as the output wavelength with an efficiency which has not been seen previously.