Quasi-phase matching of third harmonic generation in corrugated discharge capillary

摘要

Quasi-phase matching third harmonic of Ti:sapphire laser was measured by propagation through corrugated discharge capillaries. The 1 cm long capillary with periodical varying inner radius was used with corrugation frequency of 200 urn. The longitudinal plasma density was periodically varied by a discharge current ablating the inner capillary walls, altering the refractive index accordingly. Average plasma density measured was 10~(18)cm~(-3) at minimum corrugation radius. Peak laser intensity was 10~(10) W/cm2 allowing enough pondermotive energy to the electron for high harmonic generation.