Laseranordnung

A laser system effects frequency doubling by means of a laser medium within a resonator, the maximum achievable efficiency for stable laser operation being determined by the maximum achievable non-linearity ( eta H) as defined by a mathematical equation relating the stimulated emission cross-section ( sigma ), the characteristic small signal amplification (G0) and the emission frequency (v) of the laser, the resonator reciprocation time ( tau R) and the number (n) of longitudinal oscillation modes in the laser medium amplification profile, the cross-saturation factor ( beta ) characterising the interaction of the modes, and the linear losses ( alpha ) of the resonator. The equation is eta H = (( alpha /G0) + 1) multiply (1 + (n - 1) beta )( sigma tau R/hv), where h = 6.6262 multiply 10-34 Js and sigma , tau R and beta are chosen large enough to give stable laser operation with the highest possible efficiency. USE - In ophthalmology or for pumping titanium-sapphire lasers or femtosecond lasers. ADVANTAGE - The design provides an efficient and stabilised frequency-doubled laser system or am intra-cavity frequency-summed laser system with almost diffraction-limited beam quality.