Frequency-doubled solid state laser optically pumped by frequency-doubled external-cavity surface-emitting semiconductor laser

Laser apparatus, comprising:

• a laser-resonator including a crystal gain-medium doped with at least praseodymium, said crystal gain medium having first and second opposite ends;
• first and second intra-cavity frequency-doubled OPS lasers, each thereof arranged to generate and deliver light having a wavelength between about 430 nm and 490 nm;
• an optical arrangement for delivering light from said first intra-cavity frequency-doubled OPS lasers praseodymium into said crystal gain-medium via said first end thereof and an optical arrangement for delivering light from said second intra-cavity frequency-doubled OPS lasers praseodymium into said crystal gain-medium via said second end thereof, said light delivered from said intra-cavity frequency-doubled OPS-lasers for energizing said gain medium and causing fundamental radiation having a wavelength between about 500 nm and 750 nm to circulate in said laser-resonator;
• and
• wherein said laser-resonator includes an optically nonlinear crystal arranged to frequency double said fundamental radiation thereby generating ultraviolet radiation having a wavelength between about 250 nm and 375 nm.