Optically pumped solid-state laser oscillator

DETAILED DESCRIPTION The present invention has been made in light of the foregoing circumstances, and it is an object of the invention to provide an optically pumped solid-state laser oscillator in which a stable output is obtainable under a wide range of environmental temperatures without need for employing a temperature controlling mechanism.
In order to achieve the above and other objects, there is provided an optically pumped solid-state laser oscillating device comprising: an optical resonator for outputting a laser beam of a predetermined wavelength, the optical resonator having a predetermined optical absorption band and being excited in response to a light having a wavelength falling within the optical absorption band; and an excitation light sOurce for emitting a plurality of semiconductor laser beams and applying the laser beams to the optical resonator, the plurality of semiconductor laser beams having wavelengths different from one another.
At least one Of the plurality of semiconductor laser beams has a wavelength falling within the predetermined optical absorption band.
In operation, when the semiconductor laser beam from the excitation light source is incident to the optical resonator, an active material in a crystal of the excitation light source is excited and a population inversion occurs.
Fluorescent light emitted from the active material is resonated by a resonator, thereby performing a stimulated emission and thus.
For example, a Nd:YAG crystal has an absorption band for absorbing an excitation light having a wavelength in the range of 806 to 811 nm, and the wavelength thereof is varied by about 0.
25 nm/deg.
when an environmental temperature around the semiconductor laser source is varied.
The excitation light source emits a plurality of the semiconductor laser beams, so that even if the wavelengths of some of the semiconductor laser beams are out of the absorption band, at least one of the laser beam has a wavelength falling within the range of the absorption band.
Hence, a stable output is obtained regardless of the change of the environmental temperature