Spatio-temporal control of THz emission

Abstract Intense THz sources are expected for further progresses in nonlinear science and technology. Liquids like water durable continuously-reusable under intense laser irradiation emission though such studies on from targets so far limited. Polarisation fine control of is demonstrated with a tilted micro-thin flow by the two cross-linearly-polarised femtosecond pulses (800nm, 35fs, transform-limited) spatio-temporal offsets. With an optimized horizontal offset at ∼11 μm between ∼8 focal spots time delay 4.7ns, circularly-polarised obtained its intensity enhancement more than 1,500-times if compared single pulse irradiation. It shown that photon-number-based efficiency to 7.1 x 10 −3 achieved optimisation double Polarisation-resolved time-domain spectroscopy time-resolved shadowgraphy imaging reveal originates volume front flow. Coupling shockwave due air-breakdown ablation-mediated mass transport pre-pulse wake-field along optical path main responsible point-like single-cycle emission.