Study of the spatial coherence of high order harmonic radiation generated from pre-formed plasma plumes

Abstract

A study of the spatial coherence of the high order harmonic radiation generated by the interaction of 45 fs Ti:sapphire laser beam with carbon (graphite) plasma plume has been carried out using Young's double slit interferometry. It is observed that the spatial coherence varies with harmonic order, laser focal spot size in plasma plume, and peaks at an optimal spot size. It is also observed that the spatial coherence is higher when the laser pulse is focused before the plasma plume than when focused after the plume, and it decreases with increase in the harmonic order. The optimum laser parameters and the focusing conditions to achieve good spatial coherence with high harmonic conversion have been identified, which is desirable for practical applications of the harmonic radiation.

Laser-Induced Molecular Plasma: A Medium for High-Order Harmonics Generation of Ultrashort Pulses

“…Laser-induced plasma (LIP) has demonstrated its attractiveness as an advanced medium for harmonics generation. Numerous atomic targets have been used for these purposes [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. Various advanced processes, such as the resonance enhancement of a single harmonic, two-color pump of plasma, quasi-phase-matching and nanoparticle-induced growth of harmonic yield, have been reported, allowing for the formation of sources of coherent XUV radiation.…”

High-order harmonic generation during propagation of the double-pulse beam through the drilled thin films

“…It means that the harmonic generation was carried out during interaction of the laser pulse with small amount of the potential emitters of coherent radiation. Previous studies of plasma harmonics were performed using significantly longer plasma plumes (0.5-5 mm) [13][14][15][16][17][18][19][20]. Further, the short delay between pulses (8 ns) did not allow the whole cloud of ablated particles to propagate the distance equal to the radius of drilled hole (*40 lm).…”

Harmonic generation from partially ionized plasma [Invited]

“…The HHG in partially ionized plasmas was actively developed during the last few years in different laboratories worldwide [91][92][93][94][95][96][97][98][99][100][101]. The developments in this area allow us to expect further amendments to this technique of coherent short-wavelength radiation generation.…”