Patent ID: 7715452

Claim:
A solid-state laser generator for performing wavelength conversion in two or more stages inside a resonator, the generator comprising: a first resonator for a fundamental wavelength, composed of first and second flat mirrors; a second resonator for the wavelength-converted laser light, composed of said second flat mirror and a third flat mirror disposed between said first and second flat mirrors, the first and second resonators being superimposed on the same optical axis; a laser medium for amplifying laser light of the fundamental wavelength, disposed between said first and third flat mirrors; and a first nonlinear optical crystal for converting the wavelength of laser light of said fundamental wavelength, at least one second nonlinear optical crystal for carrying out higher order wavelength conversion of laser light whose wavelength has been converted by said first nonlinear optical crystal, and a lens, disposed between said third and second flat mirrors; wherein: the spacing between said first lens and said second flat mirror is equal to the focal distance f of said first lens n (n is a natural number) pairs of lenses are disposed between said third flat mirror and said second flat mirror, one or all of said first nonlinear optical crystal and said at least one second nonlinear optical crystal are disposed between said first lens and a second lens that constitute one of said n pairs of lenses, and a spacing between said first lens and one or all of said first nonlinear optical crystal and said at least one second nonlinear optical crystal is equal to a focal distance of said first lens, and a spacing between said second lens and one of all of said first nonlinear optical crystal and said at least one second nonlinear optical crystal is equal to a focal distance of said second lens.