Patent ID: 7801188

Claim:
A laser, comprising: an active body capable of emitting a fundamental wave of radiation when excited, said fundamental wave of radiation having a fundamental wavelength; a resonant cavity enclosing said active body, said resonant cavity being resonant for said fundamental wave of radiation; a spectral filter to make the fundamental wave of radiation oscillate in a single longitudinal mode within said resonant cavity; a pump source for exciting said active body; a first non-linear element capable of converting said fundamental wave of radiation into a frequency-doubled wave of radiation having a wavelength that is half of said fundamental wavelength, said first non-linear element comprising a quasi-phasematching structure; a second non-linear element capable of mixing said Fundamental wave of radiation and said frequency-doubled wave of radiation into a frequency-tripled wave of radiation having a wavelength that is one third of said fundamental wavelength, said second non-linear element comprising a quasi-phasematching structure of third order; wherein the first and the second non-linear bodies are both arranged within said resonant cavity; wherein the laser is operative to emit said frequency-tripled wave as a continuous wave of radiation; and wherein the fundamental wavelength is shorter than about 1200 nm, the laser thus producing a frequency-tripled wave having a wavelength shorter than about 400 nm.